Men's-specific ski socks are built with a wider heel pocket, lower arch, and larger calf circumference to match typical male foot proportions. If you have average to broader feet, this tailored fit means less bunching inside your ski boot and fewer hot spots during a full day on the mountain.
Unisex socks can work, but they're a compromise. You might notice heel slippage or excess fabric around the calf, which can lead to blisters or cold spots. That becomes more noticeable the longer you ride. Men's socks also use men's shoe sizing, so finding your size is more straightforward.
That said, if you have narrower feet, a women's-specific sock might actually give you a better, snugger fit inside your boot. The goal is eliminating slack and slippage. For most men, though, men's-specific ski socks are the easiest path to all-day comfort and performance.