It's not shocking if you understand some of what's involved. For glass, there are lots of different chemical compositions related to color, hardness and other

It's not shocking if you understand some of what's involved. For glass, there are lots of different chemical compositions related to color, hardness and other physical and chemical properties, plus all the contamination with other materials like labels. You can't just throw it all into a big furnace and get anything except low quality glass with inclusions - and there's no market for that. Heck, ask glass blowers what COE they use and if you can bring your own colors in. Paper has a lot of the same issue, cleaning it isn't worth what you can get from it. I would guess that we might see an increase in some sort of biological breakdown of it in the future, BUT that might end up releasing a lot more carbon than simply sequestering it in landfills. I suspect that we'll see big improvement in plastics in the coming decades with better breakdown and separation options, but even there contamination will be a big problem. Metals are about the only thing really practical to recycle, at least given current prices for them.