Google tried to hire additional customer support reps but none of them got past the whiteboard code test

As a former GCP support rep, this is actually true. Their strict hiring practices prevented them from scaling up support along with their platform, so they had to contract with other IT companies to provide the necessary manpower. Unfortunately, that also meant that Google's support was manned by people not up to Google's own standards. This started to change over the last year when they got sick of the lackluster support from their contractors, but I still doubt they are able to get enough Google qualified engineers willing to work in customer support. It's definitely not for a lack of trying, though. The problem is that if you're good enough to pass a Google whiteboard exam, wouldn't you rather build things, rather than coach other people building things? I sure did.

Evangelists and Teachers definitely exist in the tech space, however FAANG companies are usually headed up by people who marginalize them in my experience.