Tbh winter tyres have nothing to do with just snow fall at all. They are a proven science and anyone who tries to deny this is just ignorant IMO.
Yes I've had a set for 2 seasons, and yes this year they've not had as much use as last year, but as soon as the core road temp drops below 7C they come into a world of their own, they're worth the money, and other than the initial cost, actually make economical sence as you summers then last twice as long
Loads of info in the 500 section as Andy has said.
All I say is that until you've done an emergency stop on a wet road from 50 when the temp is 3-5C outside on winters, vs doing it on summers, you'll simply have no idea! Happy to demonstrate it if anyone lives locally
With regards to not needing them a few years ago, realistically they were needed, but unfortunately the tyre tech wasn't there, but it is now