Mesh networks are still online storage from a users perspective in that it's limited by the users network connection. Also there is some software capable of this the problem is giving up a fair amount of bandwidth and storage capacity for somewhat safe but free backups vs paying ~50$ a year for safer backups without the headache.
PS: Popular torrent files are basically this already as they can persist a long time after the initial seeder stops seeding.
In this case, you're only limited by your network speed in the event of data-destroying event. In the normal case it's completely local, which has much less headache than any network option most of the time.
PS: Popular torrent files are basically this already as they can persist a long time after the initial seeder stops seeding.