I've played a lot of WoW in the past, but I stopped in early legion. I started playing again when Dragonflight launched, but I stopped again just a few weeks ago - in part because I can't bring myself to grind anymore.
The endgame is fundamentally the same. You pvp, raid, and/or do M+, to grind for gear, and that's pretty much it. I don't do pvp, but I've heard the grind for pvp gear isn't bad. Raids and M+ are still quite grindy though, and for better or worse they're still pretty tightly coupled. If you want to play one at a high level, you'll have to participate in the other.
Personally I've never felt like recycled content was an issue in WoW, but since you brought it up, I'll mention that they're reusing old dungeons for M+ now. There are still 8 new dungeons, but each M+ season now uses 4 dungeons from the current expansion + 4 dungeons from an older expansion so that people aren't just spamming the same 8 dungeons for the entire expansion.
If you want a game that respects your time, my suggestion is to look elsewhere - especially if you're interested in raiding. They've made some progress in Dragonflight I think, but raiding at a not-casual level still takes way more time than it did pre-legion.