Video games need as much modding support and customizability as possible for the inevitable outcome that they will die after several years, months, weeks, days, etc.

Having a bunch of options and settings for players to tinker with. Providing easy modding tools for ease of creation. Map creators so people can make their own realms. Character creation and/or customization. Tutorials, guides, documentation, about how the game works and how to play it. Providing the source code for everyone to keep.

Bonus points if you've got an indie/open source game on your hands. That's almost guaranteed to die out quick. Shoutout to the devs who do this anyways, even though it might seem like a fruitless task.