I’ve heard this argument thrown out before but my issue is always that you have a permanently declining user base since you can’t buy more copies. This is a band aid delaying the inevitable. It will not allow a game like this to live forever.
It has been released as exactly that: https://www.knockoutcity.com/private-server-edition#section-download
Isn’t that what they did? https://www.knockoutcity.com/private-server-edition#section-download
From the article:
There’s one thing, however, that Harrison recommends studios do above all others when sunsetting a live service game: let players keep playing the game on their own servers. Before shutting down Knockout City, Velan released the game as a standalone Windows executable with private server support. It’s still available to download.