Firefox is 29% Javascript, 28% C++, 22% HTML, 10% C, 3% Python, 2,6% Kotlin and 5% other

> There is no guarantee that other bugs do not flurish in the rust echosystem.

well, less likely than in C thanks to a advanced type system, e.g. allowing authors of abstractions make their API much more fool proof.

> where every malicious actor can inject malware is a big warning sign.

Very much doubt that is the case...