Not all "snow tire" conditions are similar. I drove in Iceland this March on studded tires, and boy, was I glad for those studs. There was a lot of packed snow/ice surface, and sometimes some deep. Occasionally, there was gravel/sand mixed in, but it was almost never completely down to asphalt.
Meanwhile, I live in southern New England. We almost never drive on packed snow or ice. They get out and pre-treat the roads, which leads immediately to slush, and then they plow. So slush, wet, and even dry conditions far outweigh the occasional mid-storm snow-covered surface. Before buying, consider and research according to most-common local conditions.
Just like skis: buy for the conditions you typically drive, not for the conditions you
wish for.