Why would someone burn a sizable chunk of their energy & free time to just entertain those C++ standard committee members sitting on a pile of their RSUs who intentionally delayed almost every single reasonable additions to the language. We are talking about a language that took almost 40 years to get networking support into its standard library! It is a modern museum of bureaucracy in Computer Science.
Some people mentioned the term "modern C++", let's be honest, that is mostly C++11 or C++14, you'd be lucky to get C++17. I won't call 10 years old C++14 modern. Just check where were golang and rust back in 2014 and how much they've changed & created. Modern is the term reserved for languages driven by its user community, like golang, rust, zig etc. New ideas get from open proposals that can be directly commented on by everyone to production in a few quarters, not a few decades.
I mean come on, why would someone with reasonable plan for his/her career choosing to put himself/herself onto that sinking ship called C++?
Let's be clear, learning C++ in 2023 is like migration to Russia/China/Cuba - you give away all your reasonable freedoms & funs to submit yourself to the mercy of a close group of "elites" who try so damn hard to dictate your life & work.