As per the first link:
That's fascinating, but, I would like to see the experiment include an image taken on a tripod, and compared to the final product from all this stacking. Also, he's shooting at a fairly low shutter speed for handheld, which also can be a factor, especially since he is sort of consciously attempting to move the camera slightly in the burst exposures to achieve this goal.
The final result is impressive, but, it seems that we are seeing a reduction in noise and moire rather than an improvement in sharpness.
Also, I'd like to see a comparison to an image taken with a Sony Ar7ii on a tripod at ISO 100. That might just solve the whole argument. Spend more money for a better camera. At least you don't have to worry about ghost people and cars in your images. Lord knows you'll save a lot of time and bother in post production. But, this is good to know if you're stuck with a smaller, older camera at a spectacular scene that you'll never be at again. What the heck. Fire away!