I specifically said journals subscription fees support peer review infrastructure. Yes peer reviewers are unpaid but peer review also would not exist in anything resembling its current form in the absence of journal staff moving papers through the peer review system. Associate/deputy editors are unpaid but the main editor of the journal is often paid and does provide scientific oversight and review, particularly at the margin of acceptance/rejection. The main editor of course is also responsible for recruiting associate editors who in turn are responsible for finding appropriate peer reviewers, so having a good editor who can recruit and maintain quality deputy/associate editors is key. Some journals even have staff scientific reviewers which act as a check on the occasional oversights of unpaid peer review.