Something missing in the 'grey has retired' theory
It's really common on this sub to think that grey had retired as he can make enough money from changing his youtube titles/thumbnails, but I always think this idea misses something. The podcast makes clear that Cgp grey is an incredibly cautious, risk-adverse guy. Leaving his channel up to title and thumbnail changes is essentially one YouTube algorithm tweak away from stopping working and failing to continue to bring in revenue. I guess it's still working well enough for him now as he continues to do it, but YouTube could so easily change that with no notice, which makes me think it's really unlikely he would hinge his continued income on that.
Could he have made enough money that he can just live off it for the rest of his life? It's possible, but he's probably what, mid-40s? So seems kind of unlikely? Maybe it's that his CURRENT situation means he doesn't need to upload a lot rather than he's decided to permanently finish with the channel.