What happened to sick time banking?

I once met a construction worker who had 3 years of banked sick time. He refused to take it, despite his very honest hatred of his particular job, but he still had it.

Today, you're lucky to get track-free vacation, and even that has to be approved case by case for bookings off.

So what happened? I'd love to be able to bank sick time or vacation time, but it feels like one of those previous generation luxuries we never see anymore. Is it gone forever?