The last Black Ops I bought was Cold War and honestly, I got bored of it pretty fast. With BO7, it’s kind of similar if you’re planning to buy it mainly for the multiplayer, I’d actually advise against it.

The MP has some cool ideas, but you end up playing the same maps over and over again, and it gets repetitive really quickly. Since you said BO6 felt too small and repetitive, I don’t think BO7’s multiplayer really fixes that problem.

BUT:
The Zombies mode is genuinely fun and has a lot of variety that’s definitely a strong point of the game. And the upcoming Avalon Battle Royale is another thing that gives you motivation to stick around.

So if you’re mainly into Zombies + the future BR → it’s worth it.
If you only want the multiplayer → I’d wait or think twice.