Cozy and Survival Games: Both of these game types, because there is definite overlap, often employ diagetic progression that involves crafting, harvesting, foraging, growing, and discovering the necessary items you need and upgrading what you have so that you can unlock more options. IME, these are powerful psychological drivers for players.
Though it's worth noting that
both of these types of games have begun to reach market over-saturation. I want to say either earlier this year or sometime last year, we had like
four different "go do farming stuff!" games announced within like a month of each other. That doesn't mean that these things have no lessons to teach us, but rather that we should be careful to account for both the fickle tastes of consumers collectively, and the twin issues of bad clones of popular games and mistaking "this specific game was popular" for "this specific
genre combination was popular." E.g. generally combining action-RPG and city-building is
not going to result in an interesting or coherent gameplay experience, but it unusually did do so with
Act Raiser.
MMOs and MOBAs: Having combat roles helps players understand what they are signing up for when they select a given class/character. I don't think that MMOs provide the best model for combat roles; however, I do think that MOBAs provide a better model for TTRPGs for several reasons. (1) MMO combat roles (and "the holy trinity") often involve managing aggro mechanics, enrage timers, etc. that are mostly non-applicable to NPCs played by a GM. (2) MOBA roles/classes (depending on the game's nomenclature) are more varied and informative than in MMO's: e.g., melee damage, ranged damage, mage support, mage control, bruiser, tank (less about aggro and more about absorbing damage, initiating fights, and peeling opponents for the team), etc.
The particularly important thing to note here is that a huge, huge part of the "tank" (and, to an extent, bruiser) vs all other MOBA roles is that it is about the
economy of attention, not about some absolute threat list which must always focus on the numerically top spot. Meaning, "tanks" do their job in MOBAs by being a dangerous
but difficult to kill threat. High defenses, high maximum HP, crowd control effects, punishments for attacking them, punishments for
ignoring them...and what does all that sound like? The Defender role in 4e. "Taunts" are exceedingly rare in 4e--but Marks are commonplace, and the Marking mechanic is all about the economy of attention. What risks will the Marked target be willing to take? Which is the safer bet, attacking the high-defense, high-HP Defender, or trying to geek the mage and risking both failure to actually do anything AND punishment from the Defender?
"Tanky bruiser" just means drifting Striker--and that, too, reflects some of the same ideas that went into MOBAs. Note, for instance, that the full flowering of these design ideas was pretty much simultaneous with the launch of 4e, since DOTA1 launched two years before and LoL launched two years after. There are avoidance Defenders (Swordmage), high-HP Defenders (Warden), inherently tanky-bruiser Defenders (Fighters), etc. There are light and mobile Strikers (Rogue, Storm Sorc), high-HP/regen Strikers (Barbarians, particularly Rageblood), super-accurate Strikers (Avenger), long-range/"carry" Strikers (Ranger), etc. And
support characters aren't dull, monotonous affairs. They're actually quite fun (I recall very much enjoying a support-heavy Malfurion in the few
Heroes of the Storm games I played.)
MOBAs again: MOBA character options often involve a character with a relatively small selection of powers: i.e., a basic attack, a character-specific passive, three abilities, and an ultimate ability. As a result, MOBAs often feature a large cast of characters with limited powers; however, each of these characters are often designed to deliver a specific archetypical fantasy. There are even a few upcoming MMOs, like Wayfinder, that are designed with MOBA style characters. One benefit, IME, of this design choice is that it's fairly easy for players to sink their teeth into an archetype without overwhelming them with too many options.
Though this comes with it a second lesson, not in what is done but what is not done: The risk of shallow experiences which do not grip you.
A very long (non-ranked) LoL match takes 45 minutes to an hour. A short one can be as little as 20 minutes if the enemy team performs particularly poorly (whether through bad luck, bad plays, or bad behavior). With such a narrow time window and rapid game turnover, you
need characters that are easy to get into and easy to get out of. D&D doesn't work like that. Indeed, I would argue it
can't, and trying to make it so would break it.
I've been playing more LoL casually lately, as I've met some folks who play, and a champion I like aesthetically (Aurelion Sol) semi-recently got a rework. His old design was...clunky at best,
very unintuitive, and not particularly rewarding even if you played it well. The new version, while losing the One Weird Trick that he previously had, is significantly better, and in fact one of my favorite champions to play. (I like scaling champs, and Aurelion Sol is neat because he doesn't just scale for damage, he also scales for
area and
range, which really matters as games wear on!) He became much more standard, much easier to slide right into--much less to catch on, so to speak.
But that process cuts both ways. There's nothing to
hold on to later. No depth and little complexity. 90% of games, you'll buy the same items, and only swap out 1-2 depending on the context. You'll always have the exact same suite of abilities. This, again, is good--great, even!--within the context of LoL, where matches are meant to be relatively short.
In the contest of D&D, where even for very old-school-minded players a single character should last several weeks if not multiple months of once-a-week, multi-hour sessions...having nothing to catch on can be a pretty big problem. People slide in...and the slide right back out again, having gained little to nothing from the experience. Finding the way to balance these two concerns--making it easy to get in, but also easy to get
hooked, to
stick with it, to feel
rewarded for doing so--is an extremely tricky design problem.
This is why I talk as much as I do about how "approachable" a game is (how easy it is to get into the game) and how much "depth" it has (how it leverages its parts to provide an engaging experience.) Different players want different amounts of engagement--what is just right for one player may be stultifyingly boring for another and vastly too complex for a third. The lesson to take from MOBAs is not that every character should be dirt-simple so that it can be fully explored in 25-45 minutes; it's that every game should focus on upping approachability while preserving a selection of different options for depth.