There's far more to roleplaying that job stats and builds. That might have been a feature of many of the old TTRPGs but it wasn't a feature of all of them and has never been a feature of all CRPGs.
I can remember playing many RPGs over the years where stats never came into play. You were tossed into an adventure and set loose to find your way as is.
If it's a feature that you personally look for when choosing a game to play, I can understand your disappointment. But it is not true to say the game has no roleplaying elements.
I'm a healer main. I am most definitely pressing more than Dia and Glare when I'm in a group instanced duty.
It's one thing to say that a group of highly skilled players have managed to complete content without a healer.
It's another to imply that an average skilled group of players can easily do the same thing. It's simply not happening. They don't have the tools. At best you end up with a good tank soloing bosses while the rest of the party is floor tanking because they lacked a healer.
Do I feel for the highly skilled players who enjoy healing and wish they had better opportunities to display their skill as healers than picking up the floor tanks? Yes. But the job design team doesn't seem to have grasped how to create jobs that work together as a team instead of creating jobs that are more self-reliant. They keep working toward giving jobs self-sufficiency, which isn't even needed in solo content since solo duties provide us with buffs that increased health regen and other benefits, instead of trying to make them interdependent as should be needed for group content. Such self-sufficiency causes the healing role to be greatly devalued when in a group of highly skilled players.
Fortunately for some of us healers, most players aren't that highly skilled. There is a need for us to be actual healers and not just green DPS that throws out an occasional AoE heal to keep the party from bottoming out. I had the fun of healing Tower of Zot the other night with a tank that did not use their defensive cooldowns at all. Seriously. Making sure he stayed alive meant I had little time for green DPS.
That still doesn't help those who are highly skilled, enjoy healing, and play with highly skilled players.