Basically the default with reviews is spam and difficult customers... Trustpilot's business models and incentives are basically to get people to pay them to remove these spam reviews.

Apple is basically a good benchmark. Basically if you can get 2.2 / 5 on Trustpilot you're at Apple tier service, and anything above that means you've either paid off the negative reviews or paid off Trustpilot.

Source: I'm on the receiving end of a lot of Trustpilot sales calls.