Well I guess that's what I'm asking. It has to be stored as data in some format. It should be possible to get that data and not be able to do anything useful with it. Unless the storage on the cartridge itself has some additional hardware that needs to be bypassed (which would be the breaking DRM part). Or I guess the cartridge itself has something separate from the software data that isn't easy to imitate with a cartridge of your own.

I haven't paid attention to the details of how copy protection works since the PSX, which put some information in a physical area of the disk that couldn't be read or written to by consumer hardware.