I've seen this "tiered" system at multiple Fortune 1k companies - did it come from SV or something? Or is this because of Google?

I think it's just a consequence of scale - once you are a single tenant to a building and control access, you'll need to grant your worker's access and recurring access to outsiders who don't have the same communication channels or management chain.

My experience as a $NOT_EMPLOYEEE badge worker at a different company was that all communication like mentioned would be sent to my company and my manager would be responsible for getting it to me. It happened a couple times, mostly on different holiday schedules or maintenance.

I've also seen systems where contractors are granted temporary company credentials and given a soft onboarding, and that seems to work but can cause points of friction elsewhere.

I think the question we should be asking is where the dividing line is between hiring an employee directly and subcontracting. I think the role of journalists should not be to rag on Google for situations like this, but to focus on companies whose subcontractors work for their own subsidiaries.