You’re wrong about Djokovic. For one thing, he injured the knee at the French Open but recovered from the surgery in time for Wimbledon, which was only about a month later. Even for arthroscopic surgery that’s a remarkably quick turnaround. I don’t think there’s any way he could have been back that quickly if it had been a repair rather than a removal. And in this article, he specifically said that the torn piece was removed:
Djokovic says recovering from surgery in time for Wimbledon 'right at top' of achievements.
I know quite a bit about meniscus removal since I’ve had it done myself. You’re never the same again (even Djokovic won’t be but then he might not play that much longer anyway) but you can still perform if they don’t remove too much. And most likely he’ll end up with arthritis and possibly knee replacement surgery (I maybe be looking at that even though I would like to avoid it) later in his life.