Human resources are a major component of infrastucture costs. Sure, for small teams you can have someone doing everything but at scale you lose the fudge factor.
I would also be suspicious of 1:10,000+ numbers as they often don't include people that are part of the server team but not standing in the data center. Aka Facebooks 3 person dev team, a manager, whoever designs there HW, the team spun up to do mass HW installations etc.
In the end AWS covers a lot of seperate costs which are only really obvious as you keep scaling up.
I would also be suspicious of 1:10,000+ numbers as they often don't include people that are part of the server team but not standing in the data center. Aka Facebooks 3 person dev team, a manager, whoever designs there HW, the team spun up to do mass HW installations etc.
In the end AWS covers a lot of seperate costs which are only really obvious as you keep scaling up.