[outworlder]

> There's two types of game developers: those who finish and publish games and those who write their own game engine.

Probably a true statement in a way that's difficult to verify. Nobody is keeping track of never released games, specially those that didn't really get started because so much work went on the 'engine'.

That said, there are some examples. Like Minecraft and Factorio. An existing engine might not have benefited those titles as much as they would a standard FPS game. They could be probably made using an existing engine, but the benefits might not be that apparent if you have to fight the engine and twist it to do what you want.

Going to larger studios, Elite: Dangerous has its own engine too - could they have used, say, Unreal? Probably, but then they would not be able to use many features, like the Unreal's terrain system, for their planetary landings and such(not without ugly hacks - or making it work like Starfield) and would likely have to code their own. If you are doing that, might as well skip the whole thing.

I'll still agree that in 95% of the cases there's an existing engine that will handle most of a game's use-cases. If one has access to the source code, this figure probably expands significantly.