Paradox - Stellaris would be a good example of this. However, this gets into a question of game economics and "how do we keep paying developers?" The "buy, on

Paradox - Stellaris would be a good example of this. However, this gets into a question of game economics and "how do we keep paying developers?" The "buy, one and done, no patches ever, bye" model for game development gets "this game is abandoned" and the initial sales splurge doesn't always cover the cost of development. Thus you've got DLC. If there are servers to be hosted for multiplayer lobbies, that expense needs to be paid somewhere. So a constant trickle of updates / fixes / DLC / changes keeps the player base interested, and can provide the revenue stream to maintain those updates, fixes and servers. On the other hand, looking at Stellaris DLC (or Crusader Kings) and you go "I'm gonna pay how much for that game?" while players who started from the start see it more as a "pay $20 / year for something new added to the game".