I just came home from a 3 hour trip with our Blazer RS with 21" Black Rims and I have to agree with you. I was in 4WD mode the entire trip and the 2020 Blazer RS has only 3,000 miles, so the tires are like new. I have never had a vehicle perform worse in the snow. I would say the roads were not icy, they were snow covered and blowing. I would say we had 1 to 1/2 inches of blowing snow on the roads, so the road was not snow packed. I was getting passed by other SUV's going 60 to 65. I did not feel comfortable over 55 MPH in the Blazer. It felt like the truck was floating and would start to sway almost like it had a trailer on the back that started to sway and cause the truck to seem on the verge of out of control. It was hard to keep it on the road. Never had the T/C go off or the stability control, as I kept it between the lines. I assume it is tires on the 21" RS Black Rims. I'm sure they are not meant for winter driving, but I would have assumed being brand new that they would have performed better than they did. My wife is no longer confident in the Blazer. I told here I would look into snow tires and that should resolve, but hate to have the extra expense every winter. Should have given it more thought at purchase that the 21's probably weren't the best idea for winter driving in WI.