That's fine, but call it what it is. I only objected to calling it a "replacement". There's a big functional difference between P2P and centralized architectures.
Syncthing is less purely peer-to-peer. It's easy enough set up a central server and have your devices only sync to that server because of the way connections are made.
Yes, absolutely. But that is a significantly greater requirement, each end user or workgroup running their own server. I'm not sure why I'm getting downvoted for pointing that out. It's not an apples-to-apples replacement.
This + a hosting provider would be more like an actual Dropbox replacement (e.g. owncloud.org links to a bunch of hosts).
That's not what I'm looking for. I do have a computer at home that is always on.
edit: Do people generally still turn off their home computers?
edit2: After thinking about it - what you seem to be describing is an alternative and not just a replacement. I want to replace the service that Dropbox offers with one of my own, I don't want to switch to an alternative Dropbox clone service.
Huge numbers of people only have a laptop at home which sleeps when they're at work. So the only sync service that's going to work for them is something with online storage as an intermediate step.
>>edit: Do people generally still turn off their home computers?
Yeah. My desktop computer eats up a lot of power even when idle. I do want the convenience of never turning it off, but I'd rather be environmentally friendly.