why are there so many cases of creatives working with almost no rest and giving good results?
There aren't. You just know about them, because they are spectacular. You do not hear about the cases were the work amounted to nothing or was destrucive to the existing stuff.
Also, I am fairly sure, you are talking about established artists - why else would you know them. While creativity is fickle, skill is not. Once you reach a certain amount of skill, you would deliver good results, even when exhausted.
There could also be cases, where you do not distinguish between the creative work and the manual work. I think you mix up cause and effect. You believe they deliver good results because of the no rest, and not despite of it. Ever thought, that maybe some or many of those could have delivered great results, instead of mere good results, with a more healthy work schedule? We are talking game making and that includes software development. Ever debugged for days to find a slight oversight you made while being tired... ;-)
Also you should look carefully if it is not one of those cases where the creative mind just needs to be expressed or explode ;-)