These giant retailers brought this upon themselves.
Ironically, Sears succeeded because it was great at something other stores either never did, or did poorly, over a hundred years ago: Catalog distribution, and sales from the same. When a new technology came along, the internet, Sears was way behind the curve.
Over time, prices at Sears and JCP became ridiculously high, unless you shopped sales and closeout racks. The thinning crowds, even ten years ago, told me that they'd never survive as movers and shakers in the retail world.
Walmart has shown itself to be able to respond to the challenge of Amazon. Their online sales are now doing pretty well. I've tried going that route, and have been satisfied, for the most part.
In retail, you either adapt or die.