Uninsulated shell gloves have no built-in insulation — they're designed to be worn over a separate liner glove. Think of them as a waterproof, windproof shield that blocks the elements while your liner handles the warmth.
This setup really shines in a few scenarios. Spring skiing on a warm day? Wear just the liner. Bitterly cold storm? Layer a thick liner under the shell. Skin touring and working up a sweat? The breathability is unbeatable. You get maximum versatility because you can swap liners based on conditions rather than owning multiple insulated pairs.
The tradeoff is that you'll need to buy and manage a liner system separately. But if you ride in varied conditions or tend to run hot on the mountain, a shell-and-liner combo gives you more flexibility than any single insulated glove ever could.