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Valve runs its massive PC gaming ecosystem with only about 350 employees
(arstechnica.com)
This is a most excellent place for technology news and articles.
It's not users that process refund request, recover your account if e.g. you've lost your 2FA method, or any of the other innumerable things you might need to contact Steam support for. I don't think it's unreasonable to include the staff that do this as part of their workforce.