Nice piece with lots of takeaways but I think that they tend to lock themselves in AWS. This certainly adheres to the Run Less SW paradigm but they might suffer a vendor lock later on.
We believe that the value we get from going all-in on AWS is greater that the potential negotiating power you may get by staying higher level and having the illusion of low cost switching to GCP or Azure.
This also accepts the risk that if AWS goes down, we go down.
I think both of those are acceptable risks/tradeoffs at this point.