No from what I recall they did not pre-mine DOGE, it was announced they would launch it at a particular date and they did just that, they all mining started simultaneously.
Why haven't the founders done anything innovative given the success?
The founders didn't get rich.
Jackson is a smuck who hated cryptocurrency the entire time he was doing dogecoin. Billy is a nice guy, but he wasn't some market wiz.
I don't know much about the history of the DOGE coin but, didn't they pre-mined the DOGEcoin? If they did they would have been sitting on a pretty good chunk of money IMO.