Alright let's see:

ShB: introduced the Crystarium crafter/gatherer quests. Introduced bisexual-color gemstones. IDK what people did before SHB with FATEs and whatnot. Introduced Bozja. While it's a similar timed open field instance like Eureka, it has different mechanics, different story, and its own raids. Begin adding Trusts and Duty Support. I believe they also begun going back to older content to rework it in some cases. Introduced New Game+. Introduced Ishgardian Restoration and FETEs. Trial Synthesis feature was added. Dungeon Explorer Mode was added.

EW: Introduced Island Sanctuary. Reworked the earlier MSQ to be more newbie friendly. Reworked housing lottery. Adventurer Plates. Reworked PvP entirely and it's more popular now than it was before. Added 3 whole Criterion Dungeons (which, for the record, 1 of these is like 12 dungeon paths and boss variants). Added new stuff to Golden Saucer. Fall Guys collab event was pretty in-depth, speaking of Gold Saucer. Compatibility with Xbox. Added a new deep dungeon which, while it uses the same style as POTD and HOH, is still definitely its own beast as well. Added extra glam plates and more glam dresser slots.

Dawntrail: Continue expanding all of the above features, and add in some more stuff as well. Already confirmed more criterion, and another eureka/bozja-like instance. Also adding in a whole new Beastmaster job, which I think/hope will also come with a pokemon-like pvp fight mechanic where two Beastmasters pit their pets against each other.


Yeah... I think you're wrong OP. I think the devs are adding in new content and new features all the time. All while you continue having a backlog of older content still to do.
You're just not engaging with it. Which is fine, maybe the new stuff isn't for you or the QOL features are not noticeable for you since you don't need any of it, and it's okay to say that. But in that case I'd say be more constructive with "this is what I want to see/do", and not come with this "omg game is dead, no new features", which is hyperbole and just plain false.