On the Usability of Editable Software(flak.tedunangst.com)
flak.tedunangst.com
On the Usability of Editable Software
https://flak.tedunangst.com/post/on-the-usability-of-editable-software
https://flak.tedunangst.com/post/on-the-usability-of-editable-software
To be sure there isn't a single pattern, and proprietary consoles do go out of their way to make the process as difficult as possible. But the modding scene in video games is huge, and some of the big hitters in the field (Cities: Skylines, Minecraft[1], Garry's Mod) have flourished because they made provided an exposed base and they, or the community, filled in the rest.
The real case study I would point to is Cities: Skylines. It adopted this highly customizable model early on in development. Not only has this helped them release content regularly through downloadable content (free and paid), but the DLC predominantly uses the same integrations that are exposed to the modding community, who can modify almost everything about the game.
[1] Minecraft did not actually make it easy to provide mods, but the sheer bloody mindedness of the community got it done anyway. Mojang later created a "hackable" version which employed Python.