Earlier quoted context omitted.
If you look on the thing you sign when getting a steam account, you don't actually own any of the games. Just like the MMO's, you cant play them when steam or producer decides to shut them down.
> you cant play them when steam or producer decides to shut them down. Doesn't Steam actually let people keep a game in their Steam library even if the publisher takes down the store page for the game?
Most games these days don't have a self-hostable dedicated server.
In case of Steam/Valve specifically it happened a while ago with Counter-Strike: Global Offensive. Valve replaced it with Counter-Strike 2, and while GO's client is still usable, some of its online components are not.