There is no compensation for reviewers, and usually no compensation for editors. It’s effectively volunteer work. I agree to review a paper if it seems interesting to me and I want to effectively force myself to read it a lot more carefully than normal. It’s hard work, especially if there is a problem with the paper, because you have to dig out the problem and explain it clearly. An academic could refuse to do any reviews with essentially no formal consequences, although they’d get a reputation as a “bad citizen” of some kind.