I'm thinking about the Debenhams buildings in two cities that I'm familiar with. They're huge, very old, purpose-built department stores, and I can't think of anything else they're likely to be used as.
They're far too big to be used by another retailer, would be hugely expensive to convert to office space (and probably useless in light of the recent shift to home working), and although I can imagine them being converted to interesting flats it would be very difficult to create the required parking per abode in city centres.
I do hope they aren't left to ruin 