Progress on environmental improvement takes time because of the lifetime of products.  The need for regulations was clear before the Nixon administration where agencies with regulations were put into place during the Nixon and Carter administrations that had their goals been followed would have resulted in significant improvement in environmental quality by now.
The time to design a product with improved efficiencies will take years but the product lifetimes are frequently measured in decades so if less efficient products are introduced it will be decades before there will be replacement or upgrade. The weakening of standards in the Reagan administration and failure to improvement in later administrations has resulted in many health issues in those years were the costs of that failure was paid by individuals rather than possible (though unlikely) corporate interests.