I find reviews to be useful, because I use them differently. If I plan to buy a product/service, I read the first few reviews, which are invariably 5-star, with a grain of salt. Then I click on the 1-star, because I want to know the bad points! However, far too often, I see that 1-stars have been counted, but the posts have been removed, which tells me that there really IS a problem, & I buy elsewhere.
When I do post, I often mention that I'm a retired professional engineer (if that pertains to the product/service) & why that's important. I seldom just "sound off" to see my own posts, or to say something useless, although I do click on the appropriate number of stars, even when I don't have anything useful to contribute.
In a remarkable number of Amazon cases, I've posted an extremely-negative report, & have actually gotten a response! In one recent purchase, I posted that the battery for a tire air pump literally went up in smoke, the first time I tried to charge it, & I got an immediate response. The seller sent me an entire new air pump, plus an extra battery, so I now have two working pumps. I corresponded with them, sending photos & my observations, & they ended up switching battery vendors! So some posts actually do some good.