But all other things are not equal, are they? A vital piece of software written in C that has been battle-tested and optimized throughout its two, three, four decades or more of existence does not magically improve if it gets rewritten in Rust. Not only does that not make sense in theory, we've also seen it in reality with the issues with the coreutils rewrites.
You can make a solid argument that new software written completely from zero would be better served by being written in Rust than C. But the "just rewrite it bro" types are so incredibly obnoxious and out of step with reality.