Its difficult for suburban downtown's to stay in business with the suburban population creating mega corporations who value turnover over quality. A small business cant afford the rent in strip mall's owned by giant REIT's and stocked with "franchise" players.
Most suburban cities feel they can simply build condos (and "replace" existing retail) to drive demand.
The Hippies and all the generations before them created this problem. I'm not a millennial but I think its the generation that's going to revert to quality over quantity -we've seen that with how they spend their money. The mega grocery store model fall's apart the minute you start mentioning "free trade" and "organic". Culture hasn't caught up with technology or business yet -as we've seen decentralization is a powerful thing. We've also seen that trust is hard to maintain when a company gets too big. I think we are going to see a small business revival in the coming years!