I understand the point you're trying to make about the stress on frugality at Amazon and I agree with you, but your specific points are more accurate for past Amazon. These days Amazon has become significantly more accommodating.

The door desks are more of a tradition. You can request more expensive automatic standing desks easily. The soda/food is not subsidized day-to-day, but we do get coffee and tea (and if you stay late due to work you can get reimbursed for dinner depending on your team). The hardware is perfectly fine as well. I have 2x 1440p monitors and an i7 13" Retina MacBook Pro as well as a cloud desktop (courtesy of AWS) with scaling hardware as I need it for development.

I am also at Amazon currently. You are right, its not as frugal as in the past but it is still significantly more frugal than an environment like Google or similar startups/unicorns that go for that. I have interviewed people who are horrified to see soda machines with prices. Requesting a nicer desk (which requires some ergo hoops), no daily soda/food, and decent but not fully maxed out hardware is still pretty frugal comparatively for engineers, even if they have loosened things up in the last 3-4 years from before. While Amazon now provides you hardware that is actual functional for the job, places like Google are giving you free yoga and dry cleaning.

I don't think the first two make any revenue, except in terms of data collected.

I'm sure you don't believe that Gmail's revenue is zero.

Google apps for business isnt free. I pay for gmail.