IMHO, more books should be in the public domain. According to the following source works up to 1923 are currently in public domain in the US.
https://law.duke.edu/cspd/
I know it's not as simple as picking an arbitrary year but perhaps all books up to 1950 should be in public domain. To argue otherwise seems to be more in the interest of censorship (
i.e., making books less readily available) rather than profits. Thoughts?