The whole Firefox codebase has not been ported to Rust and will not be anytime soon. So your argument doesn't hold true.
I agree with this. But just saying Firefox has X millions of lines of code doesn't say anything about the possibility for Linux to be ported to Rust.
I never said that. My whole premise is that you can't say anything like this by just saying code count on two very different projects. Maybe you didn't read my comments properly.