I actually think the majority of the discussion in recent years has been that the relics were too easy to get in Endwalker and that the grind was important, made them feel earned and prestigious, and gave people something to do as opposed to "playing other games".

I do agree that fixed grinds are better in general, because you can plan it and know exactly how long it will take. But if it's just FATEs, it's whatever. They're FATEs. You don't have to think while doing those, and can focus on the social interaction in party chat instead.