if Zephyr, a small niche company can make single (lol) single fan 4070, then my opinion is more and more that other OEMs are incompetent
nowadays, undervolt+PL often gets rid of >25% TDP for <5% performance loss. The same way there is "headroom" to OC or sell the cards already set at diminishing return TDP or v/f curve, there is (legroom?) to go smaller / more efficient
Here is another example:
Inno3D (while still compact),
used X2 on 4070Ti Super (285W) but not on 5070Ti (300W), do they really need an extra fan for 15W? Same die size btw
Not much different than 4060Ti 8GB having single fan cards but 4060Ti 16GB only having the Colorful model...