Imagine apartments built into what used to be department stores, (Oh, you’re JC Penny 203? I’m at Sears 106). Get those old arcades up and running. Set up meal stations at the food court. Once people actually live there, stores will start to move back in.
If I’m unable to finish my life in my own home, that doesn’t sound like a terrible option.
If you’ve got an open area like a department store, that’s a lot of square footage that can be divided out. Walls can be built too, not uncommon at all in commercial construction I’m sure. And there are raised floor setups in data centers to make it easy to run cabling and stuff. If they can handle giant server racks, I’m sure a couch would be easy peasy.