In my vision of the future internet, when you upgrade your phone, your old phone gets plugged into a power socket and USB drive in the corner and becomes your new selfhosting server. You have apps for Mastodon, Nextcloud, Jellyfin, Plex, calendars, whatever.
The key pieces missing are simple tunneling services (think ngrok with a GUI designed for selfhosters), easier domain name management, and porting apps to run on phones. The most difficult is the last one but I'm hopeful that virtualization will take care of that in the near future[0], and maybe things like Wasm in the long run.
EDIT: PS - If you're interested in making this world a reality, join us over at https://forum.indiebits.io/
[0]: https://www.reddit.com/r/Android/comments/ybq4ih/pixel_7_has...