CHERI is neat, but, as far as I am aware, still suffers from serious unsolved problems with respect to temporal safety and reclamation. Last I looked (which was probably after 2022 when this post was made), the proposed solutions were hardware garbage collectors which are almost a non-starter. Could that be solved or performant enough? Maybe. Is a memory allocation strategy that can not free objects a currently viable solution for general computing to the degree you argue people not adopting it are whiners? No.
I see no reason to accept a fallacious argument from authority in lieu of actual arguments. And for that matter, I literally do kernel development on a commercial operating system and have personally authored the entirety of memory management and hardware MMU code for multiple architectures. I am a actual authority on this topic.