Sure, I just don't even think it's hard to salvage it. The basic approach is right, just cut it down - though not as severely as you're suggesting because you're overly concerned with this tiny minority who get analysis paralysis at all, we're already down to like 5% of players, and of those, many can get it on everything.
... are you serious? You think only 5% of people ever suffer analysis paralysis? Or did you intend to write 55% at the wrong time and under the wrong conditions - because I suspect that is a low estimate? Because an overwhelming number of options (way outside the 7+-2 rule of thumb) presented in one giant lump and then drawing from the same daily pool of points but allowing for novas (which makes pacing significantly harder)
A lot of analysis paralysis is about presentation - and I dealt with it in two out of five players in my last group (so way more than 5%) by giving them custom-written character sheets that grouped up and laid out the options in a way that suited their individual characters. The mystic would have been a much much bigger problem.
Not every class is for everyone.
No - but we can reliably assume that people are going to, from time to time, play classes that are not intended for them. The failure states are therefore important. The secret to success of 5e (other than Critical Role), I'm convinced, is that it minimises these fail states both in number and impact - and the mystic fails on all counts.
Also important is what proportion of people a class is actually for and how obvious the class makes it who it is for. The mystic, with its fiddly nature is for a relatively low proportion of people. And with its utterly unclear theming doesn't draw people in.
So who is the Psion for? Because if the Mystic is your example, meaning simplicity isn't it, the only answer I can think of is "People who've been playing since the 2e days and want there to be a Psion class like back in the day". I can't think of character concepts that can only be covered by a Psion class.
It adds a ton because it's a completely different approach and one that actually jives with approaches from fantasy fiction, unlike all other D&D casters (very much including Sorcerers).
Here I'm going to say you're way over a decade out of date. The ridiculous parts of Vancian casting left with 4e, and stayed gone in 5e, with even the 5e wizard being a semi-spellpoint caster. Sources like WoW, Harry Potter, and even D&D itself has added the grab bag of spells to popular culture. The 4e/5e specialisation rules reward focus and limited lists. Oh, and the warlock is a thing.
All of which says to me that yes in the 90s the 2e Psion was a huge thematic improvement on the 2e wizard in many places. But that was quarter of a century ago and three editions ago.
I don't agree re: smart and your argument neither makes obvious sense logically, nor is supported by evidence, and I have a huge amount of anecdotal events that run directly against your claims. I would got as far as to say that in an exception-based system, claiming that more classes pushes players away, when all the previous editions of D&D and every other exception-based class-based game I can think of has tons and tons of classes and does great.
Let's look at the evidence.
The longest lasting edition of D&D and probably the most successful after 5e was AD&D 1e - which did not have lots of classes officially considered canon (and if you want Dragon equivalents there's the DM's guild). 2e, which did have a lot of classes did badly enough that it was caught by White Wolf games (whose classes were barely asymmetric) and badly enough that it brought TSR down. 3.0, 3.5, and 4e all also had tons of classes - and collapsed. If the evidence wasn't so one sided I'd say the sample size was too small. But it is one sided. Adding classes brings the game to a point it becomes intimidating and the D&Ds with fewest classes are most approachable and last longest.
What makes it particularly unconvincing to me is that it's the most casual-ass players who pick the weirdest classes and subclasses, utterly reliably. I hear this ridiculous claim like "new players want and need to play stuff like Champion Fighter". It's complete bollocks. New players are bored stiff by stuff like Champion.
On that we can agree - new players look for stuff they find cool.
Which is precisely why a class that "isn't for everyone" and that will give negative play experiences is to be avoided. If it's a class that promises to be fiddly and delivers on that - a geometer mage or something - that would be reasonable. But the mystic isn't promising that.
New players frequently pick complex and involved classes and engage with them really strongly - like Bard - Bard is not a simple class, it has a lot of moving parts and a lot to consider. Wizards too.
And one of the advantages 5e has over other editions is that thanks to the changes to spell prep you tangle yourself less.
Pure anecdote (but that seems to match with what you've got) but I've seen more players driven away from D&D by it not having a good class to support their concept, or because they hated the mechanics on D&D casters, than because the classes "overwhelmed" them. 2 vs 0 so low numbers but w/e.
If you want to defend the mystic or the Psion that way
give me those concepts that can't be done. This is a big part of what justifies the Artificer. But "I do magic with my mind to manipulate people" fits both an enchanter and a college of whispers bard.
I'm not saying there aren't cool concepts that can't be done. I'm asking what they are and saying just the name "Psion" or "mystic" isn't enough
Yes. They've repeatedly said they understand people want it. That's why they tried adding it early, like in every other edition since 2E.
And when it failed they added it through different routes like the College of Whispers Bard and the Psychic Warrior. They have most of the character concepts, leaving the class a near empty husk.
And if you are a person with a problem with analysis paralysis as bad as you're describing, there are bunch of 5E classes that will be an issue.
Except I'm not a person with analysis paralysis problems. I'm someone who solves those problems for other people.
Which demonstrates a profound lack of understanding of the issue. It's like thinking Paladins are just "Fighters who are a bit religious".
A closer analogy would be asking the point of introducing a paladin class if there was already a divine equivalent to the Eldritch Knight. And you know what? That could be done - the 5e paladin with their range of oaths does it.
The sorcerer is already internally powered and can pick up spells that give them telepathic and telekinetic abilities that can be cast at various levels and can trade slots up and down and can tweak their spells. What does the Psion bring thematically or mechanically that can't be done by an aberrant mind other than a lack of tentacles?
Or Rangers are "Fighters who crap in the woods", except even more extreme. Your "argument" is just a lot of extremely strong opinions about something that doesn't even really impact you, because you'd never even play it.
But you don't actually have an answer. Which is why you are going all out on the offensive and hoping that I don't notice that you are following the maxim that "case weak, attack the opposition".
And someone fumbling with a mystic would affect me because analysis paralysis affects the entire table. A well designed class on the other hand might inspire me to play it. But the mystic isn't it. And when you say it's almost what you want you're trying to get something added that would have a significant chance of making my games worse.