Servers cost money to operate and maintain.

They don’t have do do that.

And publishers aren’t interested in losing control of an IP

They don’t have to do that.

or supporting them indefinitely.

They don’t have to do that.

Now that I wrote that thrice, I feel like it reads as passive aggressive, but that wasn’t the intention. Anyway, the only requirement is to not brick the game, which shouldn’t be a problem for any game that contains a singleplayer mode.

For online-multiplayer-only games the publisher would actually have to work some solution, which costs money. I’m interested to see how that goes.