I don't think that your statement about C with C++ compilers holds true anymore. I have seen quite a few codebases that are definitely C++, but use bespoke memory management strategies where required. Pool allocators and allocation-only heaps are high on the list of things that are useful in this area, for various reasons.

I'd call most of that C with classes.

As ooposed to what? This is the core of C++, even though feature creep has opened up the language to other coding styles and patterns.

I should have said "not garbage collection" instead of manual memory management.

Reference counting, regardless how it is implemented (language primitives or library), is a garbage collection algorithm.

This is stretching definitions imho. Ref counting does not stop the world or kick in when you don’t expect it to.