Earlier quoted context omitted.
What you fail to understand is that investment in IP is not the goal, so saying it would no longer be invested in is non-convincing. You have to actually prove that research would slow down but your hypothetical scenarios are not proof. I can just as easily assert that investment and research would happen with or without temporary exclusive legal rights as. Market forces still push for improvement even without exclus…
Research the origins of IP. IP didn't exist forever. It was introduced because it was needed. If you think this is subjective, let me ask you think: you have a popular YouTube channel, your content requires paying writers, actors, VFX teams and editors. Bunch of other people copy your content freely and legally and get most of the ad revenue. You protest: you made this content, you paid for it. Please just link to me…
Why would YouTube pay ad revenue to a "bunch of other people" in a hypothetical world where YouTube could freely and legally host a copy of the content themselves, and take all the ad revenue for themselves?
They have an incentive to pay something the creator (if they think that doing so would motivate them to create more content, and hence lead to more ad revenue in the future), but certainly not to a bunch of random people uploading the same content.