There are few use cases where that 3% matter. Unless your writing real-time critical systems, which most of us aren't.
What really matters is documentation, user-base knowledge, adoption, and honestly I think Rust is doing a wonderful job in those departments.
I think far, far down the line (5-10 years), Rust will provide an unseen boom in the utilization of embedded electronics, not in that the speed is comparable to C/C++, but because you can be more expressive and organized in your usage of the limited resources. Better code is not just code that runs faster, but is easy to read and refactor, Rust is leagues beyond C/C++ in that department, in my opinion.
What really matters is documentation, user-base knowledge, adoption, and honestly I think Rust is doing a wonderful job in those departments.
I think far, far down the line (5-10 years), Rust will provide an unseen boom in the utilization of embedded electronics, not in that the speed is comparable to C/C++, but because you can be more expressive and organized in your usage of the limited resources. Better code is not just code that runs faster, but is easy to read and refactor, Rust is leagues beyond C/C++ in that department, in my opinion.