Many indoor malls have become depressing. Some near cities have become downright dangerous.
Most malls that have thrived have restyled themselves, likely at great cost. For the most part, they are upscale.
Brand outlet malls also seem to be doing well—they serve the middle. The one near me always has great deals on really good clothes.
Sears used to be the anchor store for many malls, and that has gone steadily downhill.
In a way its sad, but in a way not. Its the inevitable cycle of destruction & creation at work.