> They’re useless to cook on.

I'd say this is a bit of an overreaction. They're definitely terrible to time correctly, heat-wise. But they also can definitely cook. I've made a rib-eye steak medium rare just fine on a cast iron using reverse-sear between oven and the glass range.

The part I really hate is how careful I need to be not to damage the glass when using a heavy pan like that.