Because having them service that debt is better than having them default?

Open stack exists. If the landlord's turn you move to your own cloud or hire any one of the other cloud providers. Is it in FAAGs interest to turn on those tenants. Yes prime competes with Netflix, but if people pay for Netflix then Amazon makes money. There is a monopoly problem here, and standards for cloud are a good idea s.t. moving clouds is easier, but that is not worthy of this alarmist attitude. Operating systems had this problem and then came byte code and llvm. Clouds already have tools to try and make interoperability easier. Containers and provider agnostic tools like terraform are not even close to a complete solution but those solutions are coming if only because businesses are incentivised against this or equivalent existential risk.