Most GOG games already allow you to download a pdf of the manual and extras if they had them

I know but that doesn’t change the reality. Most PCs don’t come with disc readers anymore. Anyone who does have an external disc drive can already burn a GOG game to disc if they so choose. Or put the game on a usb-stick/SD-card/external drive all of which are more convenient options than using a disc. Shipping boxes for an outdated technology is a purely wasteful exercise for a company like GOG because most of their games are older releases and have no DRM. I see the benefit of discs for new console releases because it allows people to offset the cost of a game by trading it in. That has always been one of the aspects of console gaming. But that doesn’t hold for GOG

It’s fun for nostalgia but my pc doesn’t have a disc drive, nor even the space for one. Depending on your internet connection downloading is faster than reading from a disc even. If they were to somehow re-release old collector edition boxes that would become tempting.