Have you heard of [syncthing](https://syncthing.net/) ? It syncs a folder between devices, like Dropbox, without the need for someone else's computer. No cloud, it's just your pc talking to your phone, directly and automatically, through your home WiFi.
The encryption is meaningless unless someone physically take the drive. The os has the key, and M$ owns the OS. So it can read that data anytime it wants. So can anything running on the machine generally. It’s mostly theater.
But yes, my point was that people don’t want to because it is too much work. It needs to be easier.