Many people outside academia still don't know, so worth repeating: reviewers get no payment. That's right, they do it for free, or more precisely, it's considered part of their job and is therefore paid by their institution (their normal salary).

If peer review is the value proposition justifying paywalls, then be aware that none of the money goes to the people providing that value.

When you buy an article through a paywall, you are not paying the author of the article and you are not paying the peer reviewers. Why does it still cost so much? Because they can get away with it. Academia is conservative and changes very slowly because all actors want to preserve their prestige and status and any change may upset the current balance of power. People are used to this system, they've learned how to play by its rules (journal reputations, number of publications, citations, metrics like that).