By providing opportunity to find errors in research of people you don't like! More seriously though, peer review is usually free or almost free, reviewers do n

By providing opportunity to find errors in research of people you don't like! More seriously though, peer review is usually free or almost free, reviewers do not get anything near to the ridiculous amount of the money that "open access" journals demand. Besides, having articles on github, with all the data, so that any reader can check the results, and comment, would be much more powerful than the type of peer review we have today.