Physical copies of games is only one part of the equation of preserving games. Relying on them 100% is just as risky as relying 100% on publishers to continue selling any particular game digitally. For all we know, a day may come when all disc-based games succumb to bit rot, no matter how well one took care of them. Chips in cartridges can die. I have a big collection of retro games, and while I'd hate to see them stop working, I've had to accept the idea that some day I may have to turn to flash carts and/or emulation to continue enjoying those games. Digital backup of games is critical to keeping retro games in existence, and while it's less than ideal to lose the chance to buy a game legally, digital-only games will continue to exist because the data will be backed up.