There are nearly 50,000 commercial journals and a long tail of non-commercial journals each with teams of editors. There are probably hundreds of thousands of

There are nearly 50,000 commercial journals and a long tail of non-commercial journals each with teams of editors. There are probably hundreds of thousands of people currently serving as editors. The issue isn't editorial bandwidth, it's that peer review is currently built into the promotion and tenure structure for academics, who produce the vast majority of scholarship and thus dictate the shape of the scholarly publishing system. Academics have to publish the papers in peer reviewed journals for it to count towards tenure and promotion. And in fact, they are limited to a small set of journals that are deemed high quality enough for their fields. These journals are chosen by tenure and promotion committees composed of their senior peers and school administration. There are over 1000 R1 and R2 universities worldwide, each with hundreds of departments each with their own tenure and promotion committees. So changing the system is a massive collective action problem.