It's confirmed, the Dropbox Backup Update ruined its functionality
I've seen a lot of complaints and questions lately about why various Dropbox features have seemingly disappeared and after a long talk with yet another Dropbox customer support agent, he told me that the new update essentially removed the automatic online-only sync functionality to put more effort into "Backup" function instead.
So now to get files off your hard drive, rather than Dropbox automatically syncing & offloading them you now have to either manually move them all into Dropbox folders and then from there make them online-only OR just delete them all from the hard drive after they've been backed up. No idea why they opted for this route, but it's ridiculous to delete online-only for folders/files in your harddrive, which was a core feature of Dropbox for at least as long as I've had it (5 years). I used Dropbox to save hard drive space about as much as I used it for the purpose of backing up my files. This is easily the most regressive update of any program I've ever experienced in my life.
Now my laptop is bricking with less than 1GB of free space & I'm having to buy an external hardrive in order to even have enough storage to allow Dropbox to sync in the first place. Thanks a lot Dropbox devs, truly a genius move...