I think for some targeted things there might well be "value added" services you could offer to transparently wrap AWS. E.g. a "write-through" S3 wrapper was something I was actually looking at because some clients when I was contracting were very reluctant to trust anything but AWS for durability but at the same time AWS bandwidth costs were so extortionate that renting our own servers from somewhere like Hetzner and then proxying writes both to a local disk and to S3 and serve up from local disk with a fallback to pull a fresh copy from S3 if missing broke even at a quite small number of terabytes transferred each month.

The nice part about something like that is that properly wrapped you can change your durable storage as needed, and can easily even selectively pick "cheaper but less trusted" options for less critical data. It also allows you to leverage AWS features to ride closer to the wire. E.g. to take another example than storage, I've used this to cut the cost of managed hosting by being to spill over onto EC2 instances in the past, allowing you to run at much higher utilisation rate than what you can safely on managed / colo / on-prem servers alone - as a result, ironically the ability to spill over onto EC2 makes EC2 far less competitive in terms of cost to actually run stuff on most of the time.

> a quick and dirty MVP to get out the door while you built your own cloud solution?

Seemed to work for Dropbox.