It is changing and I saw some survey’s showing 17 around 1/2 the shops. I know for my JSON library it wouldn’t be possible without C++ 17 so it’s a loss of eyes

Yeah, thing is how much C++17 is actually used beyond the language version.

For example, C++/WinRT is a C++17 library, yet plenty of samples use C style strings and vectors.

I use a lot of core C++17 isms. They make some things doable and others clearer. But I think C++17 really helped a lot in generic programming in addition to the containers it introduced.