Google has billions of users and has thrown out everything that doesn't scale, like support or customer service. A lot of support and content moderation is done by volunteers (there's a certain hilarity to the way the world's most valuable corporation recruits unpaid labor as if it's some sort of charity) in Google Local Guides or Google Help Center type stuff.

Also, the "cost per employee" can look artificially higher because they contract out so many of the support positions they do have. I think "employees" mostly constitute management, marketing, and engineers?