Mostly because Amazon decimated corporate chains, which freed up more market for independent stores.
Most of them are tied to a coffeeshop though. But if you check your local map you might be surprised.
I loved B&N by the way, more computer-related books than WaldenBooks, but not as many as Borders.
They've broadened out into being general "gift stores". My local Barnes and Noble has a large toys section (mostly LEGO and educational stuff), board games, puzzles, music (lots of vinyl), stationery (fancy journals).
It's essentially "stuff introverts like" in a nice space.