Comment by pjmlp

You right, because the main companies with OSes that contribute to the surviving compilers that still care about ISO, are now focused elsewhere.

Apple with Swift, Google with Go, Java/Kotlin, Rust, Microsoft with C#, Go, Java and Rust.

Most modules stuff on GCC was done by a single developer, if I am not mistaken.

Notice how Visual C++ blog posts are mostly about game development related improvements, Visual Studio tooling.

Everyone else their compilers are still stuck on C++14, or C++17 if lucky.