What do people use index cards for these days?

What I use them for is irrelevant. I keep a supply of several sizes and colors on hand for different purposes. But I know I’m not the average customer for stationery items and whatnot.

I’d have thought they’d be practically obsolete by now, given the changed nature of schoolwork and educational materials. But they’re still a readily available item, even in the pens-and-notebooks aisle of a large-inventory drugstore such as Walgreen’s or CVS. Somebody besides me must be buying them. Who, and for what?