Now that my trucks carry 2-ton or 3-ton campers on the back, I find less use for 4wd but it has not eliminated its use. On the other hand, I've been carrying chains since 1989 that I have not had to use because I have 4wd. The chains have been put on ensure proper fit, but that was done on a clean dry driveway rather than sloppy mess along side a road.
As Grit dog pointed out, areas where temperature is right at the freezing point are the worst. Wet snow will pack most tire treads and turn to ice and ice will have a sheen of water on it when compressed by a warm tire. It is much easier to drive the Sierra Nevada ranges in winter than the Cascades and I drove through all of the Austrian and Swiss Alps with my 2wd Opel without having to chain up.