But since you wonder why the Trust Pilot ratings are so low. How many times did you ever leave a positive review for a website, service, restaurant? How many times did you post a complain?
Same goes for real life, not just the internet. You will likely find more people complaining about something than publicly posting a positive outcome. I am definitely NOT saying any of the Exchanges you posted are 100 percent to be trusted, but unfortunately there is a lack of balance in reviews most of the time and this makes the rating score of a website kind of unreliable. Particularly when you have on the other hand a LOT of websites with 5 out of 5 star ratings posted by bots.
Take all ratings with a spoonful of salt. Avoid Centralized Exchanges as much as possible or use them with amounts you are willing to risk losing.