I disagree. Many programming languages are here just because they're good enough, not because they are perfect. For example, C is a good enough systems language

I disagree. Many programming languages are here just because they're good enough, not because they are perfect. For example, C is a good enough systems language. However, when compared to Rust, it's worse at most important criteria, including being more error-prone and less expressive (it's absurdly simple, though). Now you say there's nothing to win, but to me the advantages are obvious: I can avoid several classes of critical vulnerabilities and at the same time not substantially lose any performance. How would that be possible without search for the holy language grail?