>If you're in an AMI on AWS, it's a virtual machine anyway, so there's virtualization overhead which is quite a bit higher than container overhead, but there's other baggage as well such as shared tenancy/noisy neighbors, and possibly oversubscription of hardware to the virtualized environment.

Can you post or cite something related to virtualization overhead being "probably an order of magnitude higher than container overhead"

Your other points are very fair.

Any mention on costs for the docker versus Ami?