> It would be cool to have a swarm of Raspberry Pi sized devices that I controlled entirely through the AWS console with AWS services, and it would open up some niche use cases like having a tiny server cluster in places where I otherwise wouldn't have infrastructure, like a remote research camp or rural community.

You’re looking for Greengrass, which is hidden away in the IoT tooling AWS provide. It allows you to run Lambda functions and Docker containers on Raspberry Pi (and smaller) sized devices, controlled entirely through the AWS console.