Cool video showing the drastic differences in tires "types" overall.
The big issue is that in reality the BEST "all-season" is close to the WORST "all-weather", where-as the worst "snow tire" is way WORSE than the BEST "all-weather" in the snow, so selection still makes a MASSIVE difference.
ie, There is a BIG overlap in tire technology. All-Weather tires are still fairly new for everyone else except Nokian tire, as they have been doing this for some time.
As a datapoint, I had a pair of Nokian WRG3 tires on a RWD conversion van that did better on snow and ice than MANY true snow tires. That vehicle was the only thing able to drive in an ice storm compared to almost every other vehicle in rush hour traffic at the time. I had buddies that were pissed that their snow tires couldn't handle it as well and that was a good 15 years ago.
As of now there is the "best of" all-weather tires that are right up there with a true snow tire. Then there are "worst of" that are still better than most "all-season" tires, but give up a lot of road noise, wet traction, and even snow and ice traction and all around suck as a "do everything" tire.
You have to research and research and research. And even then you need to decide is that the right tire for the vehicle and the way you drive.
I mean my Cadillac CTS-4 has Continental DWS06 tires on it because they handle the best in the dry, the wet and if I am caught out in the snow they will probably get me home as long as it isn't too deep (the CTS-4 is pretty low). Now, are they anywhere near the rest of my cars with "all-weather" tires as far as snow, no way, but I do have all of the other vehicles that I drive more often wearing "all-weather" tires for that reason.
I will add, the Vredestein Quatrac Pro are quiet, handle great and have great control and stopping on snow/ice. The Nokian WRG4 are a bit noisier on dry pavement and on grooved concrete can even sing a little bit, so that is a big issue I have with them. They handle good and are great on snow/ice, plus they are on the MKT compared to the MKS, so that is OK, but I would have preferred to go with the Vredestein Quatrac Pro if I could have gotten them in the proper size for that vehicle as well.