> One major gripe I have with these C++ updates is that the proportion of codebases that actually use recent C++ features (cpp17, cpp20, cpp23) is very close to zero.
Anecdotally, all the stuff I do has been minimum C++20 for a few years. If you're using e.g. Qt 6, released in 2020, you're using at least C++17 features without knowing it ; same for recent versions of boost which start depending on C++17 or C++20 depending on the features / libraries.
That's verifiably not true.
https://www.jetbrains.com/lp/devecosystem-2023/cpp/
Anecdotally, all the stuff I do has been minimum C++20 for a few years. If you're using e.g. Qt 6, released in 2020, you're using at least C++17 features without knowing it ; same for recent versions of boost which start depending on C++17 or C++20 depending on the features / libraries.