obsolescence means to become outdated, the book is referring to American women who can bring about the effect of products becoming outdated by wanting to continually have new consumer products. It does not mean to buy stuff even if you don't need it. The book is saying that this buying of consumer things that women do, has the effect of making things obsolete.
Progressive obsolescence is the secret power that women have to make things obsolete. The books writer began the modern selling of things aimed at women, that then made the husbands go and buy to keep the wife quiet. Repeatedly and progressively until we end up with how things are today.