I would add that even within physics there are massive differences, which also shows up in how grants are written. While the fundamental physics areas (like particle and astronomy) do publish a lot on arxiv etc. In the more applied areas it can often be quite different (which also applies to the use of word unfortunately). The metrics you use for your grant applications are also very different, the more applied areas often have to show impact through patents, spin offs etc., while this is less so in the fundamental sciences.

The use of arxiv etc is slowly making its way into the more applied areas, so things are moving to become more open. On the other hand in quantum we are currently seeing the opposite trend, so much research is now within startups who are absolute flush with money, but typically don't have a path to commercialisation. So they do research, but only very little of that research gets published anywhere, so the scientific process is becoming much less open.