To me Rust's main advancement isn't technical. It's that software development is first and foremost an ongoing social activity rather than the finite output of a single mind. Rewriting something in Rust shouldn't be about fixing potential bugs but about making the code safely accessible to a wider range of coders than the original (C) codebase was. Rust itself evolved mostly as a collective effort and nurtured a strong and mostly wholesome community and culture which IMO is what gives it staying power.