My initial reaction was basically one of your headlines - “Desktop apps with extra steps”. But I guess you are right that selfhosted apps are often better than plain desktop apps. Interesting idea in general.

A cool thing to have with this would be backups, designed in a way that makes it easy to manually back up on a USB drive. Not necessarily automated, but maybe with automatic reminders “You didn’t back up your data in X days - Backup now - Close”.