One fundamental difference between GCP and AWS is that AWS puts zones in different buildings in the same, well, "region," whereas GCP just isolated them in the same building.
Not the end of the world, but you shouldn't assume that by deploying things regionally with GCP you will be protected against, idk, a fire or water issue that has building-wide impact.
Who told you that GCP AZs typically coexist in the same building?
Can you provide the source of this information?
If you open for example one site of us-central1 region ( 41.17425599375981, -95.80193009453644 ) you will see that just this one site has several buildings.
Not the end of the world, but you shouldn't assume that by deploying things regionally with GCP you will be protected against, idk, a fire or water issue that has building-wide impact.