Who cares about your opinions about what number of PRs is right? They want to make more PRs (particularly to a monorepo), they need a new VCS.
Even if they weren't making a lot of PRs, Github has been melting down enough this year that they've probably encouraged customers like Anthropic to move off.
I was casting doubt on whether or not they need a new VCS to achieve their goal in the first place, not providing an opinion about the "right" number of PRs. Like most things coming out of these labs it's hard not to look at it as marketing. Their "changes merged per day" is absolutely meaningless unless you know the nature of those changes. I could make a graph like this by making tons of agent-based empty commits. That's not a problem that actually needs a solution, though. Furthermore, they _didn't even build a new VCS_, they copied one that existed and made a bunch of noise about it.