What sort of content are you actually looking for that isn't questing story/lore? I mean. There's always trials/raids to unlock, but those aren't exactly huge time investments, unless you're trying to sync/min ilvl the old ones, or you're caught up to be progging the newest ones. Which, still, once you've got them on farm, you're just left waiting for weekly resets to keep riding the gear treadmill.

Other than that, there's..? Maybe if crafting/gathering catches your interest, or making some attempt at dominating the marketboards. But nothing's stopping you from starting out with that at any point concurrently with running story quests.

Idk. Just sorta sounds like you're asking for busywork. If that's all you want, just find a thing you want to do and do it? Go hunt those mounts/minions/cards. Throw yourself into the deep dungeons. Max out all the jobs. Go glamour hunting. Try PVP.

It's an amusement park game. If you're not having fun doing one thing, try another. MSQ still gates everything, so you might still feel the slog trying to get through to something else.