Rust is already dramatically more popular and widespread than ADA ever was ( outside the US military ). Devs that use Rust say they love it. I do not believe that is the rule for ADA.

Rust is also very well suited to extending existing C and C++ code bases. I do not know enough about ADA to compare but it is my sense that it is not as strong there.

There is no ADA in the Linux or Windows kernels.