Technical capabilities of a product is obviously important, but for consumer products, I think we would all agree that here is alot more to a product than its technical specs.
There is feature set, build quality, design, compatibility, usability, pre-sales support, after sales support, etc...
Even technicals on their own do not mean much to a consumer really. Data requires interpretation, and even interpreted data requires understanding of the position of the product in the overall market, which requires category knowledge.
So reviewers do serve a purpose in my opinion beyond what a detailed technical reports would do for consumers.
Maybe what a lot of us is meaning to say is that trying to review a product without factual information on its technical performance, and based only on subjective opinions is at best a fool's errand and at worst is damaging to the larger society? Because I'd agree with that
Yet it is the norm isn't. We think people who has reviewed a lot of cars do know about cars and a guy who shows up on a video with a lot of speakers and a scope in the background knows all there is to know about speakers. Even worse, I mean forget about people buying a ****** headphone, there are people who give advice on nutrition, on exercise, on health in general pretending their personal perceptions are facts and they actually know shit because they read two articles on wiki and their buddies at the gym agreed with them..