Sure, for the typical user facing application HN readers talk about then C++ can certainly contain vulnerabilities that are worrisome. Many performance critical applications can tolerate vulnerabilities in favor of latency.
It seems to me that the world of realtime systems including avionics, autonomous control software, trading, machine learning, and more is "not useful" as per your comment. The extreme low level control that C++ offers and powerful metaprogramming allows for performance that even Rust cannot hope to rival.
The industry has moved away from C++ for plenty of these user facing use cases. Codebases like Chrome and Firefox can't just be rewritten in Rust overnight. You can try and rewrite eg; SSL libraries but that has its own host of problems (eg; guaranteeing constant time operations).
I encourage the people parroting a move away from C++ to really think about what it is that should move and what the pros/cons are. I think you'll find that many of the things at risk (i.e user facing applications) are already on their way to being rewritten in Go/Rust.
