Things at the bottom of the manufacturing pyramid (fuels, plastic monomers) tend to cost about 50 cents a pound -- chemical recycling of plastics struggles because of the low cost of the product and similarly any attempt to do anything with the vast amount of lignocellulose waste (or potential of making it with crops like switchgrass) flounders because the juice isn't worth the squeeze. So you see a lot of things like this

https://www.nature.com/articles/d41586-025-01986-0

which have the potential of better economics than turning PET into BTX chemicals but aren't so scalable since there is only so much Tylenol people can take. That said, (1) geopolymer concrete is likely to have a long service life, possibly more than conventional concrete, and (2) geopolymer concrete can be recycled

https://www.sciencedirect.com/science/article/pii/S095006181...