[notyourday]

For businesses that actually have users the biggest cost is not instances, it is the per byte billed network cost, including cross-AZ cost.

AWS cross zone traffic within the same region is not free:

https://www.lastweekinaws.com/blog/aws-cross-az-data-transfe...

and I distinctly remember getting bitten by the same kind of a bill at Google for traffic between their AZs within the same region, which makes me guess that Azure has the same business model.

If Oracle offered Zoom free traffic inside the region between different AZ's then it demolished AWS and GCP pricing.