The 1896 sale of goods act (which lasted until 1970's) was sub-titled "caveat emptor".
I read the reviews and decide what to make of some of the outliers. I also look at the profile. If there are a lot of 1 star I read them carefully. But most of all I read the "verified purchase" reviews. Ones where people have parted with hard cash.
It's not fool proof but one can eliminate a lot of the trolls, loons and liars.
I've also read some product assessments in that well known consumer magazine and found them less than helpful (washing machines, for example, you can indeed ignore advice to spend the price of a small car).
Would it be better if there no reviews?