I understand and also agree. I'm on record for wanting Eureka/Bozja to have incorporated Treasure Maps, after all
As well as the whole "Deck of Sixty for AST pls" thing.
Overall, I don't think what we have is bad. I think what we have is often left unfinished, when it could kinda do well enough with ideas from other stuff we've been having as detached features.
I'm mostly thinking of the game as how FF12 did some of its sidequests. It being a solo-focused game will naturally also have a large focus on the gameplay elements. But to me, they've been incorporated into a major portion of what FF12 was about: exploration. You were rewarded for straying off the dictated path. You were rewarded with extra areas and sidequests if you decided to do more than what the game told you.
It's why I love the concept of Variant Dungeons. They just needed better rewards.
So to me, the problem with "volume" is less so "omg we have too much and it all sucks", but rather "We have a lot, which is good, but they're simplistic. We can do better with what we've got."
Hence why I mentioned how casual content is lacking. If you notice, I say "Eureka is a FATE-only area" = can do with more stuff in it. "BLU has no application past a challenge log and carnivale" = it has potential, expanding upon it would benefit it. As well as giving more features in the same vein as Bard Performance, which don't require combat gameplay mechanics or working toward a reward to be reaped. Simply features that allow players to have fun and experiment with without it becoming necessarily "outdated" after a while. It's not just volume, but how robust the content is.
Otherwise, one thing I enjoy? POTD. Deep Dives were the absolute bomb for me. Gameplay at those levels is just unenjoyable for me at the moment, otherwise I'd definitely keep doing it nowadays. Because I had to work for something, yes, but it had more than just the obvious grindy levels.