It's not that games can't work as books, it's that books can't work like games.

Trust me, if book publishers could keep you from actually owning a physical book, from reselling it, from photocopying it, from lending it to a friend, they would. And with ebooks they do.

The fact that games are software gives publishers additional capabilities and control over the product, and they take advantage of that control to limit user control whenever possible. You just can't do that with a pile of paper bound together, otherwise they would.

This is where legislation can come in though. We need to make it legally clear that when you buy something you really own it. Renting, leasing, licensing, these ideas aren't bad on their own, but you can't call that "buying" and the venue offering these services shouldn't be called a "store". If it's called a store, it needs to be actually selling things, otherwise the entire business is disingenuous and deceptive.

Consider ebooks. Amazon has revoked and deleted ebooks that people paid for. They've ironically done it to 1984. And I think even to people living in countries where 1984 is public domain.

It's not that they can't treat games like books, it's that they don't want to. And they don't want to treat books like books either; they just don't have any control over the physical object once it leaves their hands. And before everything became downloads, games used to come on a CD, cartridge or cassette, and you could sell that just like you could sell a book, and they were powerless to prevent it. But with everything being downloads and always online, they have that power, so they use it.

You do own the game, for most games sold on GoG. (Not the copyright assignment. The "game", or "copy of the game", however you want to refer to it.) If you buy a game as a disc, in a store, you own it until you take it home and find an EULA contract that takes away that ownership. I don't believe a clickwrap contract has any legitimate effect, but I don't think the courts would be on my side.