The game basically only puts pressure on healers in normal mode multiplayer content, and that pressure comes exclusively from other players being atrocious at the game. Everyone else can just do whatever they want and nothing will change outside of some rare niche fights that have the balls to include a dps check or a tank mechanic -- and of course, in those fights, wipes are common. Shout out to Titania in trial roulette, which continues to be a crapshoot because tanks won't just do the bare minimum and turn on their stance.
But no. Outside of those niche areas of the MSQ where some dev was having a good day and decided to spread responsibility evenly, it doesn't matter what you do. If you're a DPS, you can tap [1] for the whole fight. "Who cares." There is no enrage. There's no shield to break. There's no add phase with a timer. Your performance does not matter for about 80 levels. Maybe more. And as a tank, you can get away with knowing nothing about your kit if you just single pull all of your dungeons, which is what most random tanks do by default. But if you decide to heal, then you're stuck dealing with these types of people every goddamned day. And I think this is the actual reason healer queues are always instant for this kind of content; nobody wants to put up with that for 20+ minutes. And it's only this bad because the game never encourages anyone to get better. From start to finish, you can sort of just play horribly and lean on the one person in your group who knows what they're doing. If you heal, you're stuck cleaning it up; and even that doesn't necessarily create a better healer. It just creates panicky overhealing healers who heal too much and waste MP because they're conditioned to expect a shit-hits-the-fan scenario every 20 seconds. Obviously this changes when you hit more challenging content, but we're talking about getting these people in roulettes.
To solve this, they should make hall of the novice mandatory and then update it with relevant information. If I recall correctly, the tank tutorial basically encourages you to single pull and gives out information that hasn't been relevant in years. If it changed with endwalker, then I'm just wrong on this but either way it's not like the tanks have magically gotten better so clearly it needs work. And for DPS, some kind of in-game grading system is necessary. Like, loads of DPS don't even know they're performing poorly because it's not like there's a meter in game or anything. And I can't exactly say "wow, we're seeing mechanics I've never seen before. Maybe press your buttons, DPS" because that's harassment. So the game should have a mini evaluation at the end of trials or dungeons or w/e, that only the player can see, that tells them stuff like "hey you're a bard but you didn't actually use any songs," or "we noticed you never used technical step" or "you realize samurai has a DoT, right? you should keep that up as often as possible." etc. There's already a site like this called xivanalysis, but it works off of tools we're not allowed to use, so the game devs should take responsibility and provide something similar in the game so people who don't know about parsing tools or don't want to use them can improve. Also stuff like stone sky sea should just be a setting you enable at any training dummy without having to unlock it. Loads of people don't even know it exists until they google it.