(it may have been sort of technically true at a very early stage when the game didn't really have much of a story or missions, but it's definitely not true for the finished product, which does have a more conventional narrative running through the game that you as the player are the driving force of)

They can't finish the game but unpatched STALKER SoC absolutely allowed mission critical NPCs to die or objectives to just resolve themselves by random mutant spawns or whatever, which is why all the important NPCs all have PDAs with the shit you need. I still feel like this gets pretty close.