Magnus Carlsen wrote a blog post about the World Championship

I found that the negative has started to outweigh the positive, even when winning. I have by now played against the previous generation and three leading players of my generation. Being result-oriented has worked out for me in these matches, but it doesn’t feel sustainable long term. Passion must be the main driver. It is unlikely that I will play another match unless maybe if the next challenger represents the next generation. (Alireza Firouzja is at 18 already ranked 2nd in classical chess and has qualified for the next candidates)