Good point. It is technically possible to recycle (or downcycle) borosilicate glass, but the lack of a market for recycled borosilicate glass plays a big part in why it's not accepted curbside and not often recycled. Another big hurdle would be keeping it separate from container glass, because it would contaminate the batch. And because borosilicate glass represents such a small percentage of overall consumer glass, it has yet to become viable to recycle at scale. We try to keep these daily questions simple, but sometimes that creates a lack of nuance. The question has been updated to be more precise.