The perception of cheating levels is orders of magnitude more than the actual amount.
The site does have some automated systems in place but 100% of games can't be checked as they are happening. If you suspect someone you should report them.
It should also be noted that Game Review accuracy is not a cheat detection tool as it's heavily influenced by rating and is not a direct engine correlation algorithm. I'm addition, in rating based Arenas, most games are going to be played with opponents of a similar rating.
https://support.chess.com/article/648-what-do-i-need-to-know-about-fair-play-on-chess-com
https://www.chess.com/article/view/online-chess-cheating
https://www.chess.com/article/view/chesscom-update-december-2024?alert=content#FairPlay
The site closed more than 74,000 accounts in September for fair play violations and has a full team of staff working on reports along with the aforementioned automated systems for detection.
https://www.chess.com/article/view/fair-play
That said, discussions of cheating, potential cheating, or cheat detection are not allowed in the general forums. If you want to discuss join the following club
https://www.chess.com/club/cheating-forum
I don't understand, how platform, which takes money for membership, is not able, to ban cheaters during live Arena tournaments. Whenever you see 2 hours arena, there are some people with 600 elo, who play the whole tournament with accuracity between 95%-100%, and winning 95% of their games. This is so obvious, that it is really hard, to understand, that paid plantform is not able, to handle it, and react on time.
And I will emphasize this once again - this is platform, which offers PAID membership.