Yeah, I even did one a few Months ago, as some kind of side activity, because I was bored by release of Eureka.
The big Problem around Eureka is, like you said, that it will be dead in Summer and the Devs bury every Mount, every Relic, every Minion, every Song, every Hairstyle, etc with it.
Lost forever...or till someone in a Guild is able to annoy his whole Guild, to do this Content for the Rewards.
And that is like with the Bluemage not how this Game should look like in the long run. That you need to "annoy" your Guild, to be able to play Content, because no one else is doing it.
The only reason, why this Game feels so small on Content despite having a ton of Content is that they bury everything with a Patch.
Release Pagus, bury Anemos. Release Pyros, bury Pagos. Release Hydatos, bury Pyros.
Instead of a connected Lootsystem, they just bury everything behind them. I can't trade Anemos Crystals, for Pagos Crytsals and the other way around. To help Players and still get my Gear done.
And the people who fell out of the System, will never see a chance to get this done in the future.
It is scalled depending on the Players in the whole instance as I heard, but how much fun is Eureka with 6 Players. Running around this empty Map, trying to spawn a Fate with just this small Party.
The Diadem is dead, because people did not like it. And it always baffles me, that Yoshi is not able to drop this Idea of the Diadem. Like I said "Fail Faster". He spend Time and Money for this Idea and now he is unable to drop it, because he invested time for it. While nearly 75% of the Community could have told him back then:
A whole Area just geared around Fates and more Fates is a bad Idea.
It feels like he wants to say "No, it is not unfun and boring. You just play it wrong.".
When new Players join the Game, they get the Picture, that FF14 is a MMO about Dungeons, Bosses, Raids, etc. and as soon as they hit max Level, they suddenly now get an Endgame about Trash Mob Farm and doing Bosses with 100 Players that just do super Basic Mechanics, like punching left or right. There are the Raids, but with Eureka a lot of more casualy Raids Parties stopped playing, because Eureka.
It feels like Black Desert would say "Grats, you unlocked your Awakening Weapon and not this Game is a Raids MMO for 8 Players.
I see so many people say "It is not unfun, you just don't play it effectively.".
This is a Game, I start the Game to have fun in the first place, not to feel like I am sitting at my second Job.
Or I hear "It is fun with friends.".
I got this horrible DayZ Standalone back then, when it was new gifted by a Friend.
And it was okay with friends, but I played it maybe once alone for 5 Minutes and noticed pretty fast "This is not fun at all.".
The thing that was fun was spending time with friends, not DayZ.