[HenryBemis]

I stopped using Dropbox many years ago. I switched to a non-syncing but encrypted cloud backup, with the years they changed and now they are Carbonite, that have unlimited storage. Challenge is that if you encrypt then you cannot recover "that one file" but you have to download the whole blob (mine is over 1TB).

When I need to travel and take my "burner" laptop it carries only the OS, firefox and the very few files that I copy with a flash disk.

And, SyncToy, I used it plenty 10-15 years ago.

You mentioned syncthing, if momery serves me well, Steve Gibson has mentioned it quite a few times but I haven't played around with it.