The aws and other cloud vendors markup on bandwidth is probably at least 50x. It is their moat. If they lower it their big spenders like snowflake will leave for their own datacenters
Once you are in the roach motel the path of least resistance is to buy other services from AWS rather than the competitors because of the egress charges. It is completely anticompetitive and I expect even the toothless US antitrust authorities will crack down on that.
