There are decentralized monorepos, such as gecko-dev (https://github.com/mozilla/gecko-dev https://github.com/mozilla/gecko-dev), which presumably has several f

There are decentralized monorepos, such as gecko-dev (https://github.com/mozilla/gecko-dev https://github.com/mozilla/gecko-dev), which presumably has several forks in products like Iceweasel. I think the monorepo workflows which Git isn't good at are things like branching, code review, and feature/version management. But there's no reason that Git should have to be slow just because a repository is large. It's more things like "merge commits don't scale in a monorepo", which I would agree with, but that's not related to the performance of the index data structure.