That seems pretty foreign to me. While I would definitely look at something like that (although I've never heard of either of those sites until now, thanks), it seems weird to me that people would assume what some website thinks is "best" is so accurate as to accept their recommendation without doing any research whatsoever and immediately going out to buy that.
Even when I was a kid and had a Consumer Reports subscription I never just bought whatever they said to buy I have always done my own research. It doesn't seem that difficult to me if you have at least a rough idea of what you're looking for in an item and can prioritize those things.
Products in a given category aren't usually trading off their features and price perfectly. There are some products that are significantly better than their competitors in all metrics at the same time; then most of the products in any given category are a mix of weird attempts at market segmentation and companies trying to simply scam you. Therefore it's not surprising one can often select a product that is objectively the best for vast majority of potential buyers.
The key is impartial though.