> I'll go back to something I said elsewhere. If it's so easy to move and change why is C++ still being written?

Because C++ is very very much a living and, most importantly, evolving language. It gives modern conveniences, while benefiting from existing user base and maturity. Alternatives may be better for specific emerging use cases but can’t just yet challenge the incumbent for the reasons above. One day C++ may have to yield, but at the moment it’s been actively renewed and the effort to migrate codebases to a new standard is smaller than porting onto entirely new language.