I might be in the minority, but I feel like the game is the best it's ever been.
There's a clear difference in the quality of leveling and 50 dungeons compared to 70 and later 60 dungeons. The design has definitely improved over time.
The extreme trials are tons of fun imo, and are truly worth playing again and again. It's just so satisfying to get a perfect run.
Sure, I didn't like Eureka but it's not like it's the only thing to do.
imho, if people are saying the game has gotten stale or needs an overhaul or what have you, maybe you should take a break and come back when the next major patch comes out? Fatigue is a real thing and all it takes is a break to make things feel a little more fresh again.
Just my two cents.