Mindshare death is a very large overstatement given the massive amount of legacy C++ out there that will be maintained by poor souls for year to come. But you are right, there used to be a great language hiding within C++ if the committee ever dared to break backwards compat. But even if they did it now it would be too late and they'd just end up with a worse Rust or Zig.

The biggest problem with C++ is that while everyone agrees there is a great language hiding in it, everyone also has a remarkably different idea of what that great language actually is.

As proven a few times, it doesn't matter if committee decides to break something if compiler vendors aren't on board with what is being broken.

There is still this disconnection on how languages under ISO process work in the industry.