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.