C++?? every 3 years isn't nearly as bad as say, the Rust situation, but it does mean that a linux desktop distro compiler can only compile stuff from "hip" devs writing in C++ for about 3 years after the distro release. It means if you chose to use these language features the vast majority of people will not actually be able to compile it.

So balance that. If you're not just distributing binaries, if you have geek end users compiling, maybe don't always use the latest bleeding edge C++?? features.