This does not demonstrate a sound understanding of how the public domain works, why copyright lengths have been extended so ferociously over the last century (it's shareholders who want this), nor the impact it has both on creative process and public conversation.

This is a highly complex question about how legal systems, companies, and individual creatives come in conflict, and cannot be summarized as a positive creative constraint / means to celebrate their works.

I develop copyright material from the letter and the images that I've both sold to studios and own myself. Copyright lengths are there to prevent the shareholder class from rapid exploitation. Once copyright declines to years not decades, shareholders will demand that be exploited rather than new ideas. The public conversation is rather irrelevant as the layperson doesn't have a window into the massive risk, long-term development required to invent new things, that's how copyright is not a referendum, it's a specialized discourse. Yes the idea of long-term copyright developed under work-for-hire or individual ownership can be easily summarized. License, sample, or steal. Those are the windows.