Reasons it's still in the game: 1. It works, with fewer problems than any other sync / cloud storage that I've used. 2. It has enough people using it outside of work that it's getting paying business customers (the Linux effect?) If either of these falters (if 1 falters, 2 does too) then they'll be gone. There are plenty of competitors and some even do sync well enough that people will use them. I'm rather upset that…
They were the first dominant syncing solution. Practically everything needing this feature has integrated DB. Beyond DB, the competition is a mix of Google Drive and iCloud, and maybe something else. Maybe if iOS and Android had centralized the interface to these types of features, DB would have gone away years ago, or adapted to the market.