Weren't there also thousands of tariffs removed? The economic advantages of that might outweigh any loses from tighter copyright, and I suspect was the carrot the US used to get all the copyright concessions. Everyone wants to export to the US but the US is traditionally too protectionist. Looking on the bright side of copyright. You never have to use somebody else's copyright work. You can always just make your own…
It also destroys culture. It is why we have lost a supermajority of 20th century film, art, and music. Nobody can reproduce it to preserve it, so the original creators copies are destroyed or lost and the material is then lost forever, because its over a hundred years after its creation before is freed to us.
These kinds of laws, if put in place and enforced for a century, would systemically ruin the cultures of all the participating nations and any innovation they may produce, because US IP law is so fundamentally broken that any truly creative endeavor will be crippled by false claims while anything successful will be kept behind paywalls and restricted access to control the social culture of the society for over a century, or longer if Disney gets its way.