It has ZERO to do with tread depth. I see so many people that think this way and laugh every time.
Winter tires are a different compound that doesn’t turn into rubber skies when it gets cold. Sooner you get winter tires the sooner you take advantage of them.
Almost, all Tesla “all seasons” are summer leaning. Some more than others. There is a very wide range of “all season”.
I had my all season OEM Tesla tires on my X the other day. The X is way better than the 3 in snow BTW. And there was an inch of snow on top of a gravel road that started to have frost set in for the winter. It was treacherous without my snows on. Big mistake, I thought I could get by another week or two without switching. I have the Performance snows without the deep knobby treads too. Night and day difference.
Winters vary a lot these days. And some winters you might think, why did I bother. Even on dry cold pavement, snows will grip better.
There are some all season or all weather tires that do have a very wide range of grip over wide temps. Tesla does not OEM any of them.