> It seems to me that the more sophisticated the safety a language provides is the more complex its error messages/code are. It would be so nice if we could solve both problems at the same time...

That is incredibly hard, yes. But at least if you are ok with the overhead of GC or RC then this is a solved problem - the bug in question here wouldn't happen in Go/Swift/C#/Java/JavaScript/Python/Ruby/etc. And that is most software today.

(But when you need maximal performance and maximal safety then Rust is an incredible option!)