Of course, the Internet has played a huge role in this. Shoppers see new styles more or less at the same time as the retailers and editors sitting in the front row, so fashion has become more democratized. There's still a role for insiders, but it's more as style interpreters instead of final arbiters.
Stores have a much bigger selling space with their websites, so they don't have to choose between the wide-leg pants or the skinny ones. And consumers don't have to wait for the big deliveries a few times a year.
There's always a rolling supply of new items—and things headed for clearance racks.
This isn't necessarily a bad thing for fashion.