My understanding is it has definitely been solved by the use of much thicker gloves or gloves with heating elements. But doing difficult technical climbing at very high altitudes also requires good dexterity and you are often up there for many days. Also lithium batteries don’t work much at all in temperatures that cold.

I could imagine some kind of warm water tube system that takes heat from a heat exchanger on your chest and transports it to your hands and feet, and is pumped by the action of walking. Not sure if that’s been tried before.

There’s a lot of great engineers who’ve done a lot of climbing so my guess is pretty anything that works sufficiently well to keep hands and feet warm, is also too complex, expensive or bulky to be useful in really extreme mountaineering environments.