I'm talking about people whose job is literally to stand there and greet people and open doors. In some places if they're provided a chair or stool to rest on it's considered less "posh" like wtf

You're confusing the word "doorman" to include other random unrelated jobs, like expecting the postman to also deliver your milk and then complaining that email doesn't solve that problem.

(I guess if you ordered milk online, he could, but that's not the meaning regular people assume when saying "postman")