Why the need to fork git? It works just fine for a middle-sized company with a couple hundred devs. Let's not pretend every company is Google- or Meta-sized. Personally, I think the sweet spot for a monorepo is not a conglomerate-wide monorepo, anyway, but one at a much smaller scale where you bundle all those projects together that depend on each other but not more. There is little harm in keeping things in separate repos when they have nothing to do with each other. Yes, you might have to copy the tooling but 1) the tooling is not going to be special, 2) if you have to do the copying once or twice, that's not a big deal.