Re: Still somone else's computer
"It's a fair bet that setting up a file sharing system with one of THOSE, even one that involves user names and passwords, wouldn't be all THAT hard..."
It's pretty easy - Nextcloud.
I run four of them. One of which has about 800 users. My wife's phone would have exploded long ago if I wasn't shipping photos and vids off it via Foldersync to my home instance.