Any sufficiently large system quickly reaches a point where a human has difficulty tracking what the system should look like. Google has at least tens of data

Any sufficiently large system quickly reaches a point where a human has difficulty tracking what the system should look like. Google has at least tens of data center locations, each of which will have multiple physical failure domains. There are also many discontiguous routes being announced at all of their network PoPs. They have substantially more PoPs than data centers. It very quickly gets too much to reasonably expect people to be able to keep track of what the system should look like, let alone grasping what it does look like.