There is a reason, which is the overall capabilities of the development org at a company. It takes more discipline and skill to do that consistently. Separate services are a forcing function for modularity.

But there are reasons for having more than one repo in a company, past a certain number of engineers.

I don't disagree.

My statement is that monoliths are capable of containing microservices and modular code to power them.

This is the way. Best of both worlds