To get people to switch to an upstart open access journal takes momentum out of the gate. You need to convince qualified volunteers to do peer review for a journal they've never heard of and that might vanish tomorrow. You need to convince influential insiders to submit quality papers. And you need to repeat this process for each insular sub-discipline.
one could make their own journal from a git repo or subreddit. they are just lists
The formal launch was a few months
The academics that already have tenure need to be the ones leading the charge. The niche and "low quality" journals all need to go overlay+openaccess. While Elsevier and Springer are pointed as these rent seeking machines, even the ACM and IEEE have a pretty tight noose on the flow of information.
Maybe it is as easy as a federal law that states, if federal money ever comes within 3 meters of your research, the researcher cannot assign copyright to another entity.