Avoiding getting too caught up in the semantics and categorization, but I wanted to touch on this, the thing about degenerate forms of play is that they sort of suggest an intrinsic value judgement that comes from somewhere (it's actually a really unfortunate term, given the concept of degenerate art, though I know that it disclaims some of the connotations as a technical term and instead alludes to the idea of degenerating from a specific goal) about what play is for, which is the goal from which it can be understood to degenerate.
I think the missing thing you allude to is the role that storytelling plays from a comforting perspective, there is a desire in storytelling to see certain stories play out time and time again, to see heroes win, bad guys banish, and certain morals win out, or see someone we identify with get their happy ending, even if they have to work for it somewhat. Knowing what I do about the player's life (and this is something they've agreed with) it's not shocking to me that the comfort food motivator is present, I've also known other people who have the opposite association: they want horror and misery and desperation because they feel like life is damn boring, and they want to take on the role of someone who is bound for collapse, or even to work out something as a kind of creative self-therapy, confronting a difficult father figure through the lens of a druid and her disappointed wizard father.
It's not hard to imagine, when you consider the appeal of linear JRPGs or other forms of linear storytelling, you still get to be much more creative in the execution and even construction of scenes, you still have to work for it in the form of tactical decisions and fireballs, you even make choices about where to go along the way that have consequences that play out on the journey to your ultimate known destination, and while sometimes there's tension, the other player characters can provide a source of uncertainty as your arc intersects with theirs.
Let's put aside the term 'degenerate', since it is a bit fraught (I meant it in the technical sense, but never mind). I think the key bit is in your last paragraph, on the role of uncertainty. Let me quote your example of play from the original post:
User A: Jackie was leaning up against the castle wall with a book in his hand, occasionally glancing up to check who was walking by. He had a large and volumous mustache, a breastplate emblazoned with the colors of House Tolumane, and a sword hung at his side.
User B: Marissa pauses in her stroll through the gardens seeing Jackie, after catching his eye, she raises her hand in greeting "Hello Jackie!" she says "I'm on my way to the Garden to talk to Samuel about that spell he was working on, would you like to accompany me?"
User A: "Sure!" Jackie moves to accompany Marissa, he lifts his arm as if to offer it to her, but then shrugs weakly and looks off to the side instead, rubbing the arm with his other hand.
User B: Marissa smiles sadly and she wonders if things between them would ever be the same again. The two of them walk for a minute or two in the Gardens until they spot Samuel and she calls out to him as they approach.
User C: Samuel is on his hands and knees, with a pair of Garden sheers, trimming the roses bushes, as the two of them approach he...
First of all, this is great and really interesting (not that it needs my endorsement). Players are effectively setting the scene and making statements about other people's characters (as in the Jackie/Marissa relationship -- were there limits to how much you could do this? Was it established beforehand? Do you still do it in other games?).
Anyway: if everyone has control (mostly) over their own characters, and they make statements in turn, and the players are actually paying attention as building on each others' statments (as in your example)... It looks to me as if play would inevitably throw up some unexpected situations, and test/reveal characters in ways that weren't planned. Does this fit with your experience?
I think it's also worth pointing out that some players who are looking for character growth might have a problem statement but not a solution. "My character murdered their sister while dominated, and needs to resolve that trauma" could lead to say, getting revenge on the responsible party and correctly placing the blame and pain on them, or maybe the character passes a few impressive checks against mental control later, and the player takes that a sign the character is developing an iron will so this can never happen again, or maybe the character gets a perfect counterspell off against a charm spell later and resolves the tension with knowledge/understanding of the powers that compelled them earlier.
All of those could be an acceptable outcome to a player who's set up that problem for resolution and might lead to slightly different places. In fact, the player may not even want to know who the antagonist who put them in that position in the first place is, and may expect the GM to work that open thread into something that ties together the stories of the other characters. We should be careful of considering the stories of players looking for this sort of pay off as completely prescribed. Instead, they've set up specific beats they want to hit and specific questions that need to be answered, but are open to a variety of answers and a variety of routes to get to those places.
Right! This is what triggered my 'degenerate' comment before. A problem statement is just classic storytelling. Leaving it open looks like old-fashioned 'story now' play.
My character has this big issue, let's find out how they deal with it. If you write the answer in stone before you even get there, what then?
I've had a thought about the primacy of "character" in this context that I think merits some exploration. I don't want to say this is a strictly modern storytelling tradition, but you see this a lot in fan-fiction communities, where characters have a certain intrinsic value, derived from properties that are relatively unchanging. The easiest example is probably just shipping culture, which is very focused on "I want to see Character X and Character Y in this specific, other situation."
This style has a certain essentialist view of what a character is that can drive conflict with other agendas. A character is a discrete, specific entity with (some, but not all) traits that do not change. These traits might be portrayed as the results of events in the past, and be altered slightly by ongoing story events in future, but they are essential. Traits that can/will change are usually flagged, and are planned as significant drivers of the plot. There is a fundamental divide between characters and plots: characters experience plots, they can be put into situations and react to them, but they are never defined by them. You can remove the character from the story, and bring them over to another one, you could portray the same character twice, in two different campaigns and point to them at the end of both and say "this is the same person."
This view of a character as dominant over situation is, I think, the fundamental point of differentiation that makes it clear this is a unique style from both Trad and Story Now agendas. A Trad character (in so much as "character" conceptually is important to a Trad player) really only exists in reference to the plot, and is expected to be an amalgamation of the events they experienced, even if they had personality elements they brought to those interactions, while a Story Now character is expected to struggle against their environment and learn/grow continuously in reaction to events. The former exists only in retrospect and is never complete and the latter is constantly in a state of reaction/discovery as things happen that force growth/change on them. A Neo-Trad character is intrinsically complete from conception, including opportunities to grow/learn that are already templated/scripted in from the outset.
From my end, it looks like we're dealing with different but intersecting axes, here. Like, the trad character typically doesn't change much, while the story now character is expected to be challenged (though they may not actually change much). That's one axis. Both types can bring a lot or a little backstory. That's another axis.
I think in both cases (but especially story now), turning the backstory up to eleven makes it hard to actually play the character, for the same reason it's hard to play in a setting with too much detail. If everything is already decided, anything I or anyone else does at the table risks contradicting the truth that is already established. This is why I look at these characters with detailed backstories and carefully planned arcs and wonder whether they are actually fun to play, or even possible to play at all, as written.
When I look at the example of freeform roleplay given by
@The-Magic-Sword , it seems to me that you couldn't actually plan detailed character arcs and be sure everything would work the way you planned. The same goes for backstory -- what if another player suddenly implies your two characters used to have a relationship?
