OK but $10/TB has gotta be like >99% profit margin for AWS. After massively jacking up their prices, Hetzner internet egress is only €1/TB. Also AWS encourages / in some cases practically forces you to do multi-AZ.
I remember switching to autoscaling spot instances to save a few bucks, then occasionally spot spinup would fail due to lack of availability within an AZ so I enabled multi-AZ spot. Then got hit with the inter-AZ bandwidth charges and wasn't actually saving any money vs single-AZ reserved. This was about the point I decided DIY Kubernetes was simpler to reason about.