Several years ago, a retired doctor who had worked in the scientific field during his career, told me that there is a fact in usage of materials called “a tiring of materials”. In other words, there is a wearing down of components in machinery from constant usage over a period of years that results in all sorts of accidents and mishaps.
It would seem to me that using metals, or glass, or any material over and over and over would finally result in a weaker and more inferior product. (I look for those recycled plastic bags to finally get so weak after repeated recycling that they’d just get to where they were more holes than bags, and it’s no comfort to think that the jet engine on the plane you’re riding is made from recycled soda can tabs that have been recycled time and again for years.)
With metals, once you melt it down, its the same as new, but in some materials the impurities accumulate. Recycled Aluminium for example is never used in aircraft.
Recycled plastics are never made into anything as useful as the source, usually its blocks of hardened crud that can’t even support its own weight, and is used for decks that requires a wood deck underneath for all its support.
And paper, is also always an inferior product, the fibers get broken and shorter fibers make for weaker paper.
It isn’t mentioned here but cardboard boxes are the one form of paper recycling that is not a total waste, you can tell because bundles of scrap cardboard are worth buying to make new products from. Just a couple bucks per ton.