I want a personal cloud, but one that can be hosted in an actual cloud.

Ideally, I think we would something like Sandstorm but that can be deployed on everything from a home server to a Docker-based cloud service like Google Cloud Run or... Amazon Fargate (I'm not too familiar with their services).

I don't use the cloud for scaling, but so that I never have to worry about power, internet, or machine-level security.

Just be aware that cloud providers like to end-of-life their managed service versions pretty quickly, so you should plan on doing maintenance work on your deployment every year or so if you decide to go that route.