Your country is lying to you. No surprise there, as all governments lie. There are plants specialized in recycling only the caps. For certain regulatory markets, the caps are easier to recycle than the bottles. As with anything, it’s all about what infrastructure is in place, and how well it meshes with already existing manufacturing. You do what is best suited to your local waste management. But be aware that it is by no means global or a universal (chemical or otherwise) limitation. Governments need to regulate both sides to make recycling viable.