I feel like this title here was clickbait.
Anyway, why would anyone think that a 4090 can be passively cooled without fans?
But speaking from experience I can say that the 4090 coolers that are on the gpus at present a pretty darn good.
With all the rage talk last year before the 4090 was released I'm impressed with the 4090 in general.
The Zotac 4090 that I have doesn't even kick on the fans until I think after 45 degrees Celsius. Maybe even closer to 50. That's pretty amazing for a card that powerful.
Noise is not even an issue with my 4090. Even the Zotac that people keep saying has such a terrible whining noise.
It does get noisy when you ramp up the fans to like 60 or 70% but that's never going to ever happen unless I force it to.