Remember Q4 of 2017, when you couldn't even open a Binance account since they got too many registrations at once? With the recent influx of new trading options, some of the volume could be moved towards decentralized solutions such as Blocknet, just to name a project.
Another thing worth speculating on, is people seem to HATE KYC like the plague. Imagine all the rich and wealthy people, like celebs, and people with big time careers, they might not even want to risk disclosing what they hold should a centralized exchange be compromised, which makes DEX's the best solution.
Could 2020 be the year of DEX's? Just a thought...
I think whales are also more prone to market manipulation from these smaller DEX's, I feel a little safer with a partially centralized exchange but not completely centralized.