Having spent six months in the field in Antarctica, having read a lot about the early expeditions and having seen their gear in their abandoned housing , I agree that the early explorers were knowledgeable about clothing and equipment available at the time and that they did use a lot ol Eskimo technology.. But, I do not agree that their gear was just as good as that available today.

Remember that Scott and all of his party died on his return from the pole. One of the problems the Scott polar party had was heavy and somewhat ineffective gear. Their equipment had to be laboriously man-hauled on sleds. Exhaustion and not having enough food was a major problem.

Scott and Shackleton both equipped their expeditions with Inuit equipment. They used reindeer hide sleeping bags, they used a grass that grows in Greenland to provide insulation in their boots and used heavy sealskin parkas and pants for outer wear. Ammundsen seemed a bit better prepared. IIRC, he used fabric and wool rather than hides and he made it back from the pole.

Reading accounts of some of their explorations (The Worst Journey in the World by Apsley Cherry-Gerrad), you come across commentary on how badly the reindeer bags shed hair that then got into everything including their food. And, as the bags shed, they got colder so they lost sleep. The grass they used to line their footwear would pack down and loose its insulation value and needed to be replaced fairly often. The sealskin clothing worked well but was heavy and not particularly comfortable. I remember reading several comments on how stiff it would get if it got wet.

The clothing and sleeping bag that I used about 60 years later were comfortable, warm and didn't shed into my oatmeal. It was still heavy by BPL standards but it was bombproof in conditions that put a premium on durability.