There are many ecosystems for buying and installing games: Steam, Origin, GOG Galaxy, Uplay. For modern games, they seem to just download the files into a folder and then one can directly start them. Looking at copying Steam games, one can copy them pretty easily. Also Steam has streaming available.
During LAN parties there is a common pattern. There is somebody who owns a game which is really likes. The person wants to play the game with everybody else, but the other guests do now own the game. They also do not want to buy the game. And usually the internet connection is not sufficiently fast to have everybody download the game files before everyone wants to go to bed.
I have a proposal: Let everybody at the LAN party who is physically in the same LAN (which might be physical or VPN) share all games with everybody for some fixed price. So say everyone pays 5 EUR, and then you can play everybody's games for the day. There would be peer-to-peer transfer of the games to everybody in the room. With gigabit ethernet, a 40 GB game would just take 6 minutes to transfer. If one uses an optimized broadcast to utilize the switched network performance, one would even use a pyramid scheme to distribute it. Many people could receive the game withing a few iterations.
This would also be an advertisement for all the games that people use. There would be less installation friction before and during the LAN party. And with a fixed low price, one could test drive all games. Perhaps one would really like it and buy it afterwards.
People often prefer cracked games because they can be freely copied and just work fine. Why do I have to live with less comfort only because I insist on buying the games legally? With the "LAN Party Unlimited Plan", everyone would be happy.