How does this compare to Google's in-house source control?

Most companies don't use mono-repos like this. While there are some really compelling advantages, the downsides tend to stack up as a company's codevbase grows.

It's mainly just startups and huge companies. For small companies git works fine for mono-repos and large companies can build their own complex code management pipelines for mono-repos.

I have been questioning whether agentic development changes the mono-repo vs multi-repo question.