Oh I also have shared folders with other people. We used to use it for sharing audio files between podcast presenters, which worked well enough. I have half a dozen folders in my $HOME, shared with different groups of people.

I also have Syncthing installed on my home server which gets backed up. So I have a copy of all my files backed up there, in the event a laptop goes missing or dies.

The only use case I haven't yet covered is an off-site backup of my Syncthing folder, which would be sensible. I just don't know who I can trust with it.