I worked as a SWE at Google and also at Google cloud. I both disagree with this and find it a very perplexing angle.
I think the issue is a mis-aligned (financial) incentive structure.
With the right incentive structure, challenges in either monorepo or federated repo can be overcome.
With the wrong incentive structure, problems will grow in both monorepo and federated repo.
The choice of repo simply manifests the way in which thorns of the incentive structure arise, but its the
incentive structure which is the root cause.
I think monorepo has an effect, but the bigger effect is dependencies expressed as build targets rather than versioned artifacts. When your dependencies are in the eternal present, you're forced to upgrade, or you're a blocker. And I don't think you can do dependencies as build targets well without a monorepo.
I think the issue is a mis-aligned (financial) incentive structure. With the right incentive structure, challenges in either monorepo or federated repo can be overcome. With the wrong incentive structure, problems will grow in both monorepo and federated repo.
The choice of repo simply manifests the way in which thorns of the incentive structure arise, but its the incentive structure which is the root cause.