I think you're partly making the point for them, RAII has been idiomatic C++ since before c++ was standardized. It wasn't even idiomatic c++98 to be missing it,

I think you're partly making the point for them, RAII has been idiomatic C++ since before c++ was standardized. It wasn't even idiomatic c++98 to be missing it, so to be missing it in c++20 library definitely still isn't.