I've been watching the videos by Andreas King on SerenityOS and the code is so clean that at first I wondered what programming language I was even looking at. I see the SerenityOS codebase as proof that if C++ programmers wanted to write modern, elegant, readable code, they definitely could.
In practice, though, most C++ programs are full of legacy code or are written by people who don't necessarily know about or agree with modern ways to program C++. It's easy to write beautiful code if you also wrote the memory manager and standard library in modern C++, but most people don't have that luxury.
By being created with a more modern standard library, Rust has an advantage over C++. There is no legacy code to remain compatible with and there is no real way to write "old-fashioned" Rust because the project hasn't existed for long enough. I've seen plenty of terrible, ugly Rust, most of it in my own personal projects. The strictness of the language and standard toolset helps, but it's far from a guarantee that enterprise Rust will be readable and clear.