Yeah, Google buys servers in public datacenters like those from Equinix. One "region" needn't be one datacenter, and sometimes AWS and GCP will even have computers in the same facility. It's actually quite annoying that "region" is such an opaque construct and they don't have any clear way to identify what physical building is hosting the hardware you rent from them.
Those are almost lost in the noise, compared to the big datacenters. (I've been inside two Atlanta facilities, one leased and one built from scratch, and the old Savvis one in Sunnyvale).