There totally is an impedance mismatch. It's definitely not as bad as you might think, but this is exactly the reason that I theoretically want to use C++. Art code is the perfect example of code where (a). mutability is whatever / good and (b). safety literally does not matter. Its the ultimate domain of hacking something together to make something pretty on the screen, not serious software engineering.
That said... Rust and OpenGL have quite an impedance mismatch, don't they?