archer9234 on 27 May 2016
Because carts have a lot of parts. If we're not talking about flash cards. They'd have to produce chips for ram and rom, boards etc. More stuff. It's easier to just make flash cards or discs. Plus, they're thicker. A console has to acomodate them. Like the NES front loader. Or they'll stick outside again. Flash memory is still too expensive, for 50GB games.
