One of the biggest companies manufacturing foam glass is actually based in the USA and has many production sites in Europe.

The insulation properties depend on the chemical composition of the glass. With recycled glass, the chemical composition is not fully under control and therefore they limit the amount of recycled glass.

Production of cellular glass (also called foam glass) requires, even with recycled glass, a lot of energy. That makes it one of the most expensive inorganic insulation materials.

My guess would be that insulation wasn't taken that seriously until recently, and construction probably isn't the most fast-moving industry out there.

It also has some extreme insulation properties: it doesn't look like it really absorbs or lets through any moisture or air. There might be cases where that isn't ideal.

But living on the fourth floor of an old building with central heating in the basement does make me wish all the pipes were insulated with that material instead - it's absurd to have to wait many minutes for warm water to come out of the tap or shower because so much heat is lost along the way.

Good question. I'd hazard guesses that there was a political dimension (the wikipedia article cites Soviet scientists developing the tech in 1930s) and that insulation wasn't taken seriously enough (heaters are cheaper to install and energy was cheap).

"Fibreglass" type insulation is commonly used in north america and is made in part with recycled glass.

https://www.owenscorning.com/corporate/sustainability/produc...