True, but you can use languages that avoid whole classes of bug!

I guess my only point is that CHERI may protect you from the worst abuse of those bugs, but it still doesn't mean you shouldn't use something that doesn't suffer from them in the first place!

How far should one go with that line of thinking?

Should we all be using formally verified C that e.g. the aerospace industry uses? It can prevent whole classes of logic bugs that languages like Rust couldn't dream of

Obviously, you don't need to do that for the majority of things.

My point is much simpler, if you can use something that removes bugs with no appreciable additional effort (or actually less effort), why wouldn't you?

no, but you can prove the absence of some bugs at compile time, so you don't have to figure out at run time what to do when they occur

exactly how far that can go is a matter of debate (it clearly cannot cover all possible bugs, because people have legitimate disagreements about whether a given operation is a bug or correct) but it can certainly cover the bugs cheri can detect