Nonfiction and scientific work should be treated differently than fictional works. I don't really care if Mickey Mouse goes into the public domain. But it's crazy that 100 year old scientific works can still be under copyright and illegal to distribute. These objectively have value to society, and the argument for the existence of the public domain is much stronger.
It shouldn't last indefinitely. Maybe only 10 or 15 years. I believe 99% of all works make most of their money in the first few years. Having copyright last a lifetime, let alone much longer, is just crazy.
Put a cost on renewing copyright. This is actually how it used to be. Half way through, you could pay a fee to have copyright extended. Very few people paid this fee (because most works aren't economically valuable), so most works went into public domain much sooner. Journals charge $30 to access obscure ancient papers. But I bet they wouldn't pay even $30 to keep the rights to those same papers.
Don't put everything into copyright by default. And again especially works of nonfiction or scientific papers. If the authors want that, then sure. This wouldn't fix the issues with big journals that demand it. But it still seems like a sensible idea to have copyright opt-in, not opt-out.