First, he announced he wouldn't defend his world championship, with reasons that boiled down to:
-- He didn't find it fun.
-- He no longer has enough use for the status to endure the grind.
Also, he seems to suspect one particular opponent -- Hans Moke Niemann -- of cheating, and is taking dramatic actions accordingly.
https://www.theguardian.com/sport/2022/sep/20/carlsen-v-niemann-the-cheating-row-that-is-rocking-chess-explained
That said, the infamous Carlsen-Niemann game that set this all off does NOT contain moves that look like the result of cheating.
https://www.chessgames.com/perl/chessgame?gid=2372960
In another wrinkle, Carlsen is part owner of a chess website and so on that, among other things, sponsored the tournament he walked out of.
Oh yeah -- this Ken Regan guy cited is smart. In particular, he made mincemeat of me in a casual game decades ago, when he was touring grad schools.
