Maybe i'm completely wrong, but Bitcoin's biggest issue now is that the average transaction speed is incredibly long. Won't mass-adaption only clog the networks even more? Why do all these merchants want to wait 2+hours for the money to arrive when conventional methods are much faster? If the average time to confirm a transaction is so long, won't these merchants be trading on unconfirmed transactions?

Or is it because all those merchants want to be paid in a currency that will, most likely, appreciate a crazy amount when mass adoption comes around? I'm just spitballing here.