The problems are wider than that. Besides, relying “individuals just doing the right thing and going a little further to do so” is, IMO, a trap. Fix the system instead. The little thing everyone can do is think about the system and realise it needs fixing.

you’re risking copyright nastygrams, but people still do it, and even upload preprints and full articles to scihub, because fuck that and it’s maybe free citations

Publishing comes with IP laws and copyright. For example, open access articles should be easy to upload without concern. “Private” articles being republished somewhere without license is “piracy”, and ResearchGate did get in trouble for it. It’s complicated. https://www.chemistryworld.com/news/publishers-settle-copyright-infringement-lawsuit-with-researchgate/4018095.article

Pre-prints are a different story.