I trust KDB. He will know when he cannot deliver at the highest level anymore. We are not talking about being able to play in the Premier League, we are talking about being the best in the Premier League, and I suspect he doesn't want to be anything other than that.
Personally, I would be quite happy to see him go at this point. He would then be remembered as a true great without compromise - no buts, no caveats. I think that Phil and Oscar and Rico can fill the gap. You cannot replace KDB like for like, and you couldn't replace Yaya like for like: you find a different way with a different blend of skills.
This season feels like a rocky road ahead.