I suspect the problem is as always, political. The standards committee is dominated by compiler vendors, who at this point are desperate to cast C in the dustbin of history, or at least put it in deep freeze, and are eager to push their other favoured languages like C#, C++ and so on. Therefore the committee has decided to please all parties by pleasing none, i.e., keep C stagnated, with only minimal changes that everyone manages to agree on, essentially relegated to embedded work and legacy code maintenance. And as long as C remains under ISO's grip, this won't change, sadly. C needs a rejuvenation and ISO is the last place to make it happen.
Absolutely true. C might have its own way of evolution to Modern C with quite a good standard library and mature features, but people who stay behind C++ don't want this, and even though some of them behave really aggressively if some languages like Rust or Zig or Modern C (unfortunately this is will never ever happened) try to replace C++ or take even a little piece of the pie.
C++ is not a bad language at least because lots of amazing soft already written on it, but some people accept it with all of the myriads of complex rules with their own subset and some people totally disagree with this and just want Better(Modern) C with plain and simple rules without hidden complex things which happened behind the scene, and counterintuitive features.
About Rust is everything cool except sometimes it doesn't allow you to write correct code and push you to do things in ways that you don't like. But we are programmers and some part of us is a painter :)
