I'm not sure I understand the concept of paid access to scientific research, so I'd be grateful if someone with more knowledge of the topic could explain it to me. Governments fund universities, people donate large amounts of money to universities, and a large portion of the population has student debt because of how expensive tuition is. Why are they charging for access to research at these institutions then?
Some of the journals are naturally more prestigious than others. Academics want to publish in these famous journals. The name of journals they publish in carries lot of value for an academic's career. (That's what matters for the big head dudes who manage funds / promotions, they don't understand all these open access stuff.)
Thus, the publisher has a monopoly or oligopoly on high value journals, new open access free as in libre journal cannot establish itself.
Even if you're a well meaning academic who wishes not to contribute to this oligopoly, when you are young you don't want to risk your career. When you're old there are other young people under you and you don't want to risk their career.
The big ~~head~~ belly dudes in positions of power are ones who need to understand this.