Many of these malls are on the outskirts of towns with relatively easy access to suburbia and interstates making them perfect locations for amazon distribution centers/fulfillment centers, etc..
A mall near me is managed by Simon properties. Three of the four major anchors in the mall (Sears, JC Penny, Carson Pirie Scott, Macy's) are either out of the mall altogether or on their way out very soon. The "specialty shops" and shoe stores that litter the rest of the mall are closing up left and right and this is in an affluent area with lots of money to spend.
I'm not sure who didn't see this coming, it was easy to spot when the malls started dying off.
Some of them have become nothing more than a giant garage sale location.