@stefano Totally agree and I wanna add that often you don't even to self host to Own Your Data, you can start small with stuff such as:
- backing up your photo on your desktop/laptop using the gold old cable and an app supporting PTP protocol (Windows and Mac have at least one preinstalled while on BSD and Linux you have many options to download from package repositories), no iCloud or Google Photos needed
- choosing DRM free ebooks, music and games and keeping a backup of them
- using Syncthing to sync your data across devices