I didn’t mean that the games were open source but that the software you need to get those games is. Also, the reason game disks aren’t sold anymore (at least for PC) is simply because hardly anyone buys them. Buying it online is simply easier. The only issue is with that is that you can’t be sure that you can always download them. But this is again only a worry because copyright prohibits distribution from everyone. You can pirate pretty much every game that’s ever existed, no matter how old, but it’s very hard to find old games legally.