Magnus Carlson just had a meeting with FIDE to say he will not defend his title for the World Chess Championship.
https://www.unibet.co.uk/blog/other-...-championship/
https://chess24.com/en/read/news/mag...pionship-title
Basically he's tired of the out-of-date format, has little to gain and doesn't have the motivation. Magnus is not retiring from chess, he just won't defend the title. Ian Nepomniachtchi will play Ding Liren instead, the runner up in the candidates tournament, for the title in 2023.
For the record, this post would fit in any one of a number of different forums, but ultimately I decided to put it here.