[pjmlp]

Most of the companies that you named, nowadays don't care about C++ as much as you think.

The work in clang and GCC is mostly done by volunteers, big names like Apple and Google rather focus on LLVM itself for their languages.

Microsoft seems to have layed off quite a few people, and is mostly focused on keeping it going for existing projects, in the context of games, as second language paired with .NET, CPython and JavaScript runtimes.

The last framework they published (C++/WinRT), its baseline is C++17, with no plans to upgrade it.

They just released an updated memory model for C# for low level coding that should be competitive with Swift and Rust unsafe models.