system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What actually stops online games from being played cross platform?

I'm curious after seeing the CoD game being refunded because people who bought it on one platform couldn't play with everybody else. Are the games that different when played on different hardware? Are consoles more different than, say, a cheap laptop and a huge gaming rig? What gives?
gpt
Between Console and PC, PC players have the advantage of being able to use the much more precise mouse input, which would lead to very lopsided skill levels for the most common games. Between consoles, Microsoft forces developers to host online games on first-party servers which you can't access from other consoles (I think Nintendo does this too). Playstation is the only console that has ever support cross-platform online, but the only example that comes to mind wasn't even between the same game: EVE Online and Dust 514 took place within the same servers but you couldn't directly interact with the players of EVE from the PS3.