I think "mandatory physical versions" kinda misses the point of the issue, tbh. It's bad digital rights laws that are the cause of the problems that you've mentioned, not a lack of physical media. DRM has been around a lot longer than digital downloads of games, and shutting down a game's online services affects purchasers of physical disks just as much as digital downloaders.
Besides, mass-producing physical media is expensive, and I'd rather not give publishers another excuse to make games even more expensive than they already are.