Do those highly available developers have the same quality as the Rust developers you could get, though? (On average.) I'd wager there is a correlation between interest in deeper topics as required by Rust and good long term design and quality. I've seen how marvelously efficient a small team of very talented people can be be. To replace them with the average highly available developers you would need far more than doubly the people and some extra manager, just because communication scales so badly. The 10x developer is a myth, but I think the 5x development team is realistic in the right circumstances.

Disclaimer: Neither do I claim to be a very good developer, nor do I think you, the reader, is only average. Just given that you are reading Hackernews is a strong indicator for your interest in reflection and self improvement, regardless of your favorite language.