I come under other - I am a university librarian that works in Scholarly Communications.
The APC charges do vary across the journals and yes, the most prestigious ones tend to be more highly priced but I wouldn't say this is exactly true. The authors don't generally pay for papers themselves...
That’s usually fine, the copyright rules around the versions of articles and what you can do with them at each stage are complicated but one that is usually permitted is to allow the author to give copies to people for their own use.
I work in this area and tbh, you are misunderstanding the nature of this. This is not about fees to publish in High JIF journals, the charges are levied against journals regardless of Impact factor and impact factor doesn’t have much to do with this tbh.
The basics are that the costs of...