Syncthing is a free, open-source peer-to-peer file synchronization application available for Windows, Mac, Linux, Android, Solaris, Darwin, and BSD. When I tried to use it a few years ago with my web server, I had issues with the software and I had to abandon it.
I installed it again last year, not knowing what to expect. For the period of time I used it, I was happy to not experience even one issue. Of course, was only synchronizing one folder from my laptop computer to my hosted VPS.
As far as I can tell, it will always be free. That alone makes it worth using. Over time, it can only get better. It’s obviously not as polished as services like Dropbox and Google Drive, but that isn’t a big deal to me. I was using it to synchronize files on my laptop computer with my server, which I couldn’t even do with most services because they used too much memory.
To be fair, most of the other services that sync files are free to an extent. As far as I know, only Google Drive, Mega and pCloud offer more than 10 gigabytes of space for free. I rarely use anything but Google Drive for temporary storage these days.
Some things are easier with virtual drives, but they aren’t safer. I originally started using a WebDAV share for everything, but then I scaled it back. I now use the WebDAV server only to host my password database, accessible from all my devices, and to update configuration files for the Nginx virtual servers (other than WebDAV).
Up until earlier this year, my workflow included FTP transfers. I no longer use FTP for anything. I have a private instance of this website on the server that feeds the real website with updated data with the click of a button. This website is completely static.
I don’t use Syncthing anymore because I no longer need it. I suspect, however, that I’ll be needing it within a year or so, to synchronize files from my laptop computer with computers owned by relatives. Most of my nieces and nephews, along with my grandchildren, are now schooling from home due to the COVID-19 pandemic. Who knows how long that’s going to last.