By product review aggregator I mean a service similar to kayak. The website would display product reviews from all over the web from both experts and general consumers.
Monetization is usually through affiliate commissions, advertising, and eventually data analytics.
If you have something in mind that is 1) different than what anyone else is doing, 2) What you're going to do will be better, 3) You are confident that your version is needed and wanted, and 4) you have the time, and money to make it and promote it, then I would say yes.
If you can't answer yes to all those questions then it's probably not worth the time.