Fresh and dry snow which isn't too deep is not like sand. And on the beach you have rarely asphalt a few cm below the surface.
I understand the fat bikes offroad and in deep snow, but not in the snow conditions I commute in a city with snow removal on the bike lanes and a long, cold winter. When there is a snow storm at -10 to -20°C, the snow isn't wet and heavy, you can easily cut it with narrow tyres. If I'd leave the city, I probably would need a fat bike.
It all depends on where you ride. How much snow, what kind of snow...