The world currently spends about €7.6 billion per year on subscriptions to academic journals according to one report. If all journal articles in the world were published in journals like PLOS One, we would spend €2.6 billion on publishing. Compared with today’s expenditures, humanity would save €5 billion every year.
Research must be reliable and publication is part of our quality control system. Scientific articles get reviewed by peers and they get screened by editors. Reviewers ideally help improve the project and its presentation, and editors ideally select the best papers to publish.