With all respect to PeerJ and eLife, I'm hoping that we can do a bit better than replacing monolithic, closed-access publishers with monolithic open-access publishers. Personally, I'm hoping that something akin to the Wordpress model takes off - supply powerful journal publishing tools free/cheap and let a thousand journals bloom. Scholastica [1] is the only one taking this approach that I'm aware of (disclosure: friends). It started about a year ago by several University of Chicago students and seems to be getting some nice traction, starting with law journals.
[1] https://scholasticahq.com/