A tremendous amount of retail just died in the 2000s, with only a few survivors. Either folding, or being bought out and merging with other companies that folded.
Amazon accelerated what you describe in every quantifiable way and it was undoubtedly baked into the overall strategy. Yes, the situation was already terminal thanks to the Internet and poor online shopping execution by the incumbents, including Walmart, but overlooking Amazon’s involvement (going so far as to call it not their fault) and pointing at Walmart as the disease itself is a tiny bit of revisionism.
Am I the only one old enough to remember discussions in older forums like these about how brilliant Bezos was to identify and exploit such a now-obvious opportunity? It was obvious then to the point of being damned near Amazon’s entire thesis.
Amazon certainly didn't help their bottom line, but it wasn't the nail in the coffin either.
I’m not sure at this point, both are horrible corporations I’ve resisted as long as I can can, yet both regularly siphon money from my checking account.