Why is Rust not more popular in ML and secure edge computing?

Disclosure: I am not a Rust developer, I am a Python developer looking to learn a lower level language. I recently had a post about whether I would/should need to learn C/C++ before learning Rust, the overwhelming sentiment was that I shouldn't bother.

That being said, I work in Data Science/Data Engineering/ML and I see C/C++ used everywhere. In automotive/aerospace applications, in edge computing etc. Why is Rust not more common? Is it just the gravity of these legacy codebases or is there a functional reason? I know Rust is more secure. Is it as fast and otherwise as flexible?

Does Rust trade-off speed or flexibility for security compared to C/C++? I know this is a painfully simplified question so please take the question with a grain of salt

Thanks!