Yes, and figuring out how to get orders of magnitude more housing production at dramatically lower prices is one of the most socially and morally important problems in the world today.
Not really. Most of the cost of housing is land anywhere it’s expensive. We have the technology to stack dwellings vertically. Where that’s illegal and there’s lots of demand housing is expensive. Otherwise not.
Apparently labour is ~35% of the cost of a house [1] though I imagine this varies a lot depending on the house being built, type of construction, location etc. Still, seems safe to assume labour is a large part of the cost.