I think review websites are used out of convenience by most people, while you can most likely find the most accurate and up to date information about most casinos here in the forum, the format in which the information is presented is probably not the best for the person which just wants to find a good casino where they can gamble.
Review websites are third party sites so basically you can not rely on them to make decisions for your money, where to make deposits, where to bet and so forth. You can read their reviews and consider them as valuable references only. On your side, after reading valuable reviews, you have to make your own due diligent research. Combine reviews from different review sites together with your own research will be good.
So gambling review websites do in fact fulfill a need for those gamblers, however this also exposes them to become victims of scams as it is not rare at all to find websites which exchange fake reviews in exchange for money.
There are neutral (good) review sites but their are biased (bad) review sites. The later sites will be keen on promotion and advertisement income for their teams, they don't care about what they write in their reviews, true or untrue, they don't actually care. So if you rely on such biased review sites, you have higher risks to use scam gambling sites. Because good gambling sites don't have need to hire such services to write biased reviews about their products.