> have a competitive advantage in the market

In theory, yes, but there are two problems:

(1) You need to either hire or train someone to write in Rust, and neither is trivial amount of effort. And at the end of the day, you need to push features out. Let's be real: you can find someone to write JavaScript to do full stack development, anywhere in the world, for a cheap price. Rust? The code may be more robust and easier to maintain in the long run, but it's hard to do that unless you already set up a team for that.

(2) Most software companies don't actually care that much about the language they use, the tech stack, or their infrastructure in general. Remember there are lots and lots of software companies that are not Google/Meta etc, and they are not at the bleeding edge of have state-of-the-art infrastructure. Saying that as someone working at a company with thousands of developers, and there are millions of old, ugly, almost unmaintainable Perl code in our core infrastructure running right now. From outside, it all looks fine.