It can be a bigger issue than you'd expect. Water-absorbent knee pads have no treatment to repel moisture, so when snow melts against them—whether from powder kicking up, sitting on a snowy chairlift, or just falling—the padding soaks it up like a sponge. That trapped moisture makes the pads heavy, cold, and uncomfortable against your skin.
The real trouble hits on chairlift rides and during rest breaks. Wet pads can actually freeze in cold temperatures, turning your protective gear into stiff, icy shells that are miserable to wear. They also take a long time to dry, so you're stuck with damp gear the next day.
Water-absorbent pads really only make sense in dry, bitterly cold conditions where snow stays powdery and you're unlikely to get wet. For most skiers, spending a little more on water-resistant pads is worth it—they shed light moisture and snow, staying lighter and warmer throughout the day.