I thought we already knew that supernovas don’t produce all heavy elements, and that cosmic rays and neutron star mergers make up for (some of? most of? all of?

I thought we already knew that supernovas don’t produce all heavy elements, and that cosmic rays and neutron star mergers make up for (some of? most of? all of?) the rest. Here’s a video discussing it. To be fair, they do point out that this is a recent discovery. https://youtu.be/lInXZ6I3u_I?si=JGKs-yUc718JUWzh https://youtu.be/lInXZ6I3u_I?si=JGKs-yUc718JUWzh