So a game key card then?
But, one of the biggest downsides of going nand storage for games, compared to discs is a much higher cost per unit
Sony isn't getting rid of discs because of the limitations of the technology - otherwise, they would be R &D ing higher capacity blu-rays (or maybe something else). They're doing it because most gamers are now digital so don't want physical, and also because they want more control over selling games themselves. So, all of these suggestions for cartridges or whatever seem entirely to be missing the point.