I have to admit, my experience with Syncthing is not what I'd call smooth. It's great when it works, but I didn't find it trivial to set up, the sync didn't work all the time, and then I was running my own storage/backup system.

I use Joplin with OneDrive and it works great. Setup was clicking a couple buttons. My employer provides me with 1 TB of storage. The free version gives you 5 GB and OneDrive standalone gives you 100 GB for $1.99 a month. I'm just a user but I'd encourage anyone to go the OneDrive route with Joplin rather than messing with Syncthing.

And on top of it I'll add that Syncthing added a feature called "untrusted device encryption"

https://docs.syncthing.net/specs/untrusted.html

So you can set a node in the cloud and set an encryption key between two endpoints, and whichever nodes that have the directory synced but doesn't have the encryption key will never have access to the decrypted data.

I use it for simple off-site redundancy.