This is the very reason I dumped Dropbox. Used to be great - I just created symlinks to all my normal data folders in the main Dropbox folder and all of those folders would then be real-time (ish) backed up to the cloud without me ever having to touch anything or move all my stuff into the Dropbox folder. Then they decided to drop support for symlinks…
They weren’t - they were on my file system and using symlinks in my Dropbox folder pushed them up to my DB account as well.