I just haven't enjoyed cod multiplayer since mw2 2009 imo since the formula has lacked 4 things:
1: map pool diversity. Imo the games have overly standardized the map design to lack unique maps leading to a diverse map pool. This trend started with black ops 1 and got worse. There have been attempts to correct this that failed in the opposite direction like mw2019 which had too many open maps without a clear design intention.
2: sandbox diversity. mw2's sandbox had the most playstyle and game options. The sandbox since then has largely become standardized with pretty formulaic ways of playing the game that lack unique methods of interacting with players and the sandbox.
3: skill based matchmaking in non ranked game modes. This is seemingly in black ops 7 but I doubt it's enough
4: innovation. Cod has not significantly innovated its formula since its founder Vince Zampella and his veteran staff of devs have been removed from the franchise. It has been copying titanfall (the game made by vince and his team at respawn), repeating old designs as "fresh", and not being the innovater of the fps market but the "safe" option.
its major innovations were with mw2019 gunplay, black ops 4 stim system which did not mesh with that game having some of the worst map design in the franchise, and black ops 1-2's skin progression. that's it.
This is just multiplayer btw. Zombies was kicking in black ops 1-3.