Jeff Bezos could be forgiven for feeling ambivalent this morning. On the one hand, the bankruptcy (and likely liquidation) of Sears is a good thing for Amazon, as it represents the elimination of another competitor. But it’s also a chilling reminder of mortality, like passing a grisly car accident on the side of the highway. Sears, after all, was the Amazon of its day: A bona fide behemoth, an “everything store,” even an innovative delivery business. Shopping at Sears was one of the basic tasks that marked someone as a member of the American middle class. If Sears can fail, then there's nothing that can’t.

As has been widely chronicled in the business press, Sears was badly mismanaged by Eddie Lampert, its chairman and CEO. If Warren Buffett is the cuddly grandfather of American capitalism, investing in solid, well-managed businesses so they can prosper in the long run, Lampert is the sleazy uncle who shows up to the family reunion each year with a different girlfriend and new sports car. The hedge fund titan stripped Sears (and its subsidiary Kmart) for parts, selling off its valuable businesses and its best real estate to other companies . . . that Lampert happens to own a substantial stake in. He refused to invest in the business, which is why your average Sears and Kmart today feels like a shop in East Germany circa 1983.

But Sears’ decline didn’t occur in a vacuum; its downfall cannot be attributed to Lampert’s mismanagement alone. We know this because it deteriorated in concert with other quintessentially middle-class American brands: J.C. Penney, Sears’ closest analogue in the world of middle-class department-store chains, is flailing. So is Macy’s. So something else is going on.

The easy explanation is the internet. But that doesn't explain everything, either. TJX, the parent company of TJ Maxx and Marshalls, both of which barely have a web presence, is booming. So is Nordstrom.

If America’s economy increasingly looks like a barbell—lots of poor people, lots of rich people, very few people in the middle class—its commercial landscape increasingly does too. TJX sells clothes at a steep discount. Nordstrom chases the affluent. Both are thriving while the middle is shriveling. Dollar stores are enjoying massive growth, too; in 2017, the top three chains opened a combined 1,800 outlets while Sears and Penney were shuttering stores as quickly as they could.

This trend is visible far beyond department stores. Sales of Budweiser, the epitome of mid-market beer, are collapsing in the United States. What are Americans drinking instead? The TJX and Nordstroms of beer: Super cheap beer, like PBR, is thriving. So are expensive craft brews. The restaurant industry is undergoing similar segmentation. Red Lobster has struggled in recent years. Outback Steakhouse and Applebees are suffering from similar indigestion. In their places, fast casual chains, which are cheap and quick, are stealing market share. And pricey steakhouses like the Capitol Grille and Fleming’s are thriving too.

Successful businesses are all alike; failing businesses all fail in their own way. Eddie Lampert may have scuttled Sears on purpose. But he was fighting against a broad reorganizing of the U.S. economy that left Sears without a real customer base. Lampert, who's a billionaire after all, would be unlikely to shop at Sears. And neither will his laid-off workers—they'll be at the Dollar Store, instead.