You can do anything in the game that you have unlocked (or unlock things that you skipped before). Max level is more like a pause in the story than a destination.
What have you enjoyed so far that keeps you subscribed? You say you don't like quests. You don't like dungeons/trials. You're not interested in any of the things mentioned in the reddit post.
Things not mentioned in the reddit post:
Crafting and gathering
FATEs
Island Sanctuary
Eureka and Bozja
Chocobo Racing
Doman Mahjong
Seeing how much gil you can earn through market board flipping, workshops and all sorts of other sources
It's really up to you. If there's nothing you can find that interests you, then it could be that you need a different game. What we want changes over time and there's nothing wrong with saying "this is no longer right for me".
