This is exactly my point. Winter brings a variety of challenges that aren't just sheet ice (again, the ONLY condition where studs actually work for you). Across rain, slush, bare pavement, the million different types of snow, and ice, the only tire able to handle all those conditions safely is a modern studless winter tire. And there's increasingly very little air between the performance of studs and studless on ice, too. Studless tires provide grip on ice not only with a very flexible compound, but also a porous structure that wicks the water melted by the weight of the vehicle in the split second the tire acts on that surface. That melt water is what makes ice slippery. By removing it, and allowing the tread pattern and compound to then key with ice's rock-like surface, grip is facilitated. And to repeat a conclusion from my article above, that grip is provided in a communicative way that enters slides progressively. When studs start to spin, they lose grip instantaneously, with no communication ahead of time. No one prefers that kind of behavior.
And that NAF test says the same thing in its conclusion. To paraphrase it: studs are good on ice. If you don't just drive on ice, the studless options are the better choice.