I think this is not entirely true. I ran the last dungeon a couple of times now and I can tell you that there are groups who still wipe on it. This is why I started playing as a healer. I might not be the best heal, but at least I don't die and can ress back people if needed on bosses.

In addition to that, many healers at max level don't know how doom works in different scenarios (e.g: when its just heal to max remove or when its esuna remove). I can tell this based on running Delubrum on a daily basis for relic.

Some people will find some content harder than others, I think SE's goal is to make things doable by everyone when it comes to MSQ.

That being said, I agree that trials as MSQ with a full new team can wipe a lot. But I saw people not accepting help in MSQ trials cause they wanted to figure out the mechanics. Which is all nice and cool if it was on extreme, but not when 7 other people are just trying to finish the freaking story... please make a party finder if you wanna do a blind learning party for a normal trial...