Here at Google, one of our most popular microservices frameworks enables microservices to be assembled into servers. If one microservice calls another one in the same assembly, it won't touch the network, and is quite optimized. There's no reason that microservices have to all run in separate binaries, but when it's useful it can be done easily enough without having to change your code.
I find my self doing the opposite. I’ll often create a Cloud Task that will call the same server that created it, just to make sure that another container will get spun up to handle the load if needed. Using Cloud Run this way quite happily for a mix of OLAP and OTAP workloads.
