Well what can I say?My street for example... Im still looking for the 2 wheel drive car,without chains,that can drive up my street when iced over. That my 4x4 without chains can.Been here 13 years,havent seen it ONE time.Not one time.

4x4's? Right tires? Up and down all day long.Thats equipment,not experience(beyond having a properly equipped vehicle under them) moving those vehicles up the road.

To make it worse,we have people leaving in vehicles with road tires going down.EVERY YEAR,without fail,a couple wind up in my neighbors yard,.....hit ice,slide,cant turn and poof.In his yard. Thats not experience/driver skill,its equipment again,tires without grip.Physics.

Snow tires,no issue at all If they have enough experience to crawl down that section and turn.

Hence I say its Both,equipment and experience that gets you through snow and ice.Equipment trumping skill in most cases (You can have a yahoo go too fast for road conditions,see it all the time)

Sand and gravel vrs snow and ice...apples and oranges.