Have you ever wondered why in The song of ice and fire/Game of thrones universe the north-of-the-wall is so isolated and technologically and ecologically so goddamn backward? It's not like they choose to isolate themselves from all the southern Westeros, and their goods, since they go raiding beyond the wall all the time and are occasionally known to trade with smugglers, even though southerners for some unknown and completely illogical reason chose to ban it and seem to treat them only by indifference at best and direct aggression at most.

First you might think that wildlings simply don't have anything to barter with, but that can't be true. Ecogically the north-of-the-wall is more or less directly comparable to real world's Canada, Fennoscandia and northern Russia. Those places, in real life, have traditionally been quite harsh places to live but they do have one resource that nobody else has, and that is excellent quality furs. Sole reason the English and French went to colonize Canada and Russians to Ciberia was the control of the fur trade. It was important enough for real life great powers and i don't see any reason it wouldn't be so for their Westerosian counterparts.

If anything, it would be even more important for them since the climate in Westeros seems to have those cyclic "little ice ages" (unsurprisingly, the colonizations of North American taiga and Ciberia both happened when the fur demands scyrocketed during the real little ice age, imagine if that happened dozens of times in your lifetime) that are really harsh, last for several years and are regular enough that locals see them as comparable to normal yearly seasons.