The rust blog post covers this. Subtree performance is terrible on larger repos and they didn’t land something that would fix it on medium sized ones. That’s why they went with a better maintained solution that scales.
replyPlus Josh seems to do waaay more - dynamically exposing monorepo directories as a separate repo.
replyI wish all the effort into things like JJ and Pijul was going into solving those sorts of things instead!