It’s a lot easier to shit on a big corp. Intellectually lazy, too.
(edit: the point being that at least one of those tools existed when they started Piper if I have the timeline correct).
On a single project? Verry much doubt either of them do
The point is that either product should theoretically have the ability to handle Google's load. They were both built for scale. If I have the timeline correct, they existed at that point. I would expect those organizations to have positively salivated at the possibility of having Google as a customer; they would have bent over backwards to make it support Google's workflows.
The ROI of such a choice vs going custom is the interesting question.
Of course, if I have the timeline wrong, then the discussion is moot.
Lots of tiny repos like GitHub? Easy sharding problem. They don't even need Paxos. One large monorepo? Everything changes. Let us not forget that GitHub cannot even handle the Homebrew repo be cloned and updated by Mac users and asked them to switch to a CDN.