Do you mean Kramnik or Hans Niemann?

Kramnik ((ab)using his status as a former world champion) accused several other top level players to the point that one of them committed suicide.

Niemann allegedly cheated (In my personal opinion as a decently rated but certainly not elite chess player, he probably did cheat in this particular game, though proof was never given and probably never will) at a high level chess tournament and was ostracized by the chess community for a while. He has since rejoined and continues to play at a high level.

Hans Niemann most likely did not cheat in the famous game where he won against Magnus Carlsen in the Sinquefield cup. Or at least, there is no credible evidence for cheating, and Carlsen actually did not formally accuse him of cheating either.

Hans Niemann cheated in online matches when he was younger though

Interesting. Maybe I am not getting something: it sounds like his cheating accusations cover some kind of an online chess tournament. Why does this even matter? Why would people care that much? Shouldn't they be focused on face-to-face world championships, etc...?

> Kramnik ((ab)using his status as a former world champion) accused several other top level players to the point that one of them committed suicide.

There is no evidence of suicide, and he had multiple drugs in his system when he died.

> he probably did cheat in this particular game

This is a fringe opinion at this point in time, even though it was obvious he did not cheat on day 1.