I agree with most of the responses here, but one thing that I think is worth noting is that not all AWD systems are built the same. The really, really good ones come from Subaru, Audi, and some Volvo’s. With good tires and a competent driver, these are usually really good in slick conditions. A lot of AWD systems though are more of a “mild AWD” where the car primarily FWD but can get some assistance from the rear. Those systems might give you efficiency gains compared to some other AWD systems, but performance wise they might not be dramatically better than FWD. So that’s worth considering I think.
Frankly if you have to ask if you need AWD, then you don’t NEED it. But it’s nice to have and pretty fun if you’re a psycho like me who actually likes winter driving