It is certainly fascinating how fast the entire landscape is changing (and not only in retail). I have shopped at Walmart only a handful of times, mostly because I do not care for the large super-stores outside of Costco (I know where everything is). And I've never really cared for their website.
But as for Amazon, we've had periods where the UPS truck is delivering packages 3 - 4 times per week. I love it: the sheer quantity of items they carry, the reviews, return policy, Subscribe-n-Save. They completely upended the market and show no signs of stopping. (I am, however, not wild about their Prime video functionality).
Locally, I've been seeing shuttered superstores like Kmart and Sears turned into churches, office space and, most recently, those kids jump/trampoline centers (took my son to a birthday party there a few months ago). It's especially interesting to see the local mall try to reinvent itself to hold onto their retailers. Ours now has a luxury movie theater with a bar, full menu, etc.