There are issues with practicality—there simply isn’t time to review everything that is published. I recall that Wikipedia toyed with this idea (they wanted to have admins approve all edits) but there weren’t enough people willing to act as peer reviewers to get the job done. Also, this would not be a very prestigious (or interesting) position for a scientist, and so it would not be an in-demand job unless it were highly incentivized. If we believe David Hull’s explanation of incentives in science, which claims that scientists seek recognition by being cited, then being a reviewer is anathema.
There are issues with practicality—there simply isn’t time to review everything that is published. I recall that Wikipedia toyed with this idea (they wanted to have admins approve all edits) but there weren’t enough people willing to act as peer reviewers to get the job done. Also, this would not be a very prestigious (or interesting) position for a scientist, and so it would not be an in-demand job unless it were highly incentivized. If we believe David Hull’s explanation of incentives in science, which claims that scientists seek recognition by being cited, then being a reviewer is anathema.