No its Just that at some point disk speed provides marginal improvments for most games, especialy since most games were designed with hdd drivers in mind . And sd vs ssd in steam deck are at that point. There are exceptions to that, but they are pretty rare ( alghtough i cant remember one right now but i know i watched one comparison where nvme disk provided actual reasonable benefit compared to sata so i imagine its even bigger with sd card ). So unless you play very specific game a lot that you know benefits from fast disk speed then it dosent really matter that much.