This old lady remembers when Pittsburgh had 3 major department stores, all in downtown before the malls sprang up. In one of the biggest malls, Century II, there were branches of those department stores, plus Sears, Penneys and Montgomery Wards. Well, one by one, the department stores died. The 3 stores downtown all closed and before long the mall locations went belly up. Century III is no more and other malls are in bad shape.
Plenty of reasons and not just Amazon. For one thing, not too many people want to get dressed, get into their cars, drive over to the malls, then sometimes spend an hour trying to find a parking space (mostly around the holidays). But even worse is the crime rampant in malls. Gang bangers are now doing business in them. Every once in a while a shooting occurs. People have also been robbed and I've heard of a few sexual assaults as well. Mall owners collect a hefty rent from the tenants, but they are too cheap to provide any better security other than some unarmed security guards. So decent people are staying away in droves and shopping online.
And a number of these stores have done themselves in through their stupid business decisions. Remember Penneys catering to the perverts and doing away with sales? Yeah, that worked out well, didn't it? Or Sears doing away with its catalog, but replacing it with a god-awful website, not to mention selling inferior merchandise.
The virus isn't killing them; they've been dying long before COVID 19. The virus is maybe just the last nail in the coffin.