The problem is that many bureaucracies attach some kind of point value to journals on this list, and a different on that list and so on. It's reforming those that is a problem, especially since according to their metrics, which are defined by counting the papers in journals in the lists, everything works perfectly.
That's irrelevant. Researchers are forced to publish in high-impact journals to preserve their career, and any newly created journal has zero impact.
Furthermore, some countries/universities enforce a journal whitelist, and evaluate the eir researchers based on the number of papers published in the pre approved list if publications.
And because those bureaucrats are often distributing public funds among those researchers, they should also have an interest in the results of that research being accessible to the public, and as many researchers as possible.
Of course, sending papers to OA journals, going the extra mile to cite them, and preferring them to non-OA alternatives when any paper will do (e.g. when you are just providing some examples of applications of X, without being exhaustive, and you can find some in OA and others in non-OA journals) does help.
But yeah, many scientists are paid by slow-moving bureaucratic machines that probably don't care about the issues involved and just want to see them published in old, well-established big-name journals, and not a new upstart that everybody else suddenly wants to consider more important.