Rust is a lot simpler than C++ or Scala. It has some upfront complexity wrt. C or Zig, but that pays off when dealing with larger programs, where avoiding subtle bugs becomes much harder.
Now do C++! He didn't say it is simple; he said it is simpler than C++.
Now, I'd say they're on the same order of magnitude for simplicity. The huge advantage Rust has is that it tells you when you got it wrong, whereas C++ says "OK, I will put the toast in the fridge."
