I hear you and it's a totally valid point. We could start paying reviewers tomorrow. I'm not convinced that adding a monetary incentive to the peer review process doesn't have its own serious negative consequences, but I'm certainly open to the idea that that's a potentially better version of the system than what we have now. It's certainly a difficult business decision to push through, given the universal lack of anyone doing so industry-wide, but that doesn't make it the wrong thing to do, and it certainly could be a differentiating factor if done well (ie by speeding up the review process a publisher might be able to increase author satisfaction and also increase article output, which in an OA world has a direct revenue impact).

I do have an issue calling it a monopoly, however. At best you can call it an oligopoly. The top 5 publishers publish about half the total articles each year [1]. So half the research is published by a combination of hundreds of smaller publishers (both for-profit and not) or independent scholarly societies. And then within the top publishers, they are absolutely in competition with each other, which becomes readily apparent when you dig into the royalty deals that publishers offer scholarly societies for the rights to publish their journals, which continue to get richer for the societies (which poses a whole different interesting problem in terms of the collateral damage to modern-day scholarly societies if or when the business model blows up).

[1] https://journals.plos.org/plosone/article?id=10.1371/journal...