This is literally a shilling campaign. All those positive reviews that you can see on 1xbit's Trustpilot review page, are completely from their campaign. These reviews are published in less than 3 days, the latest publication of a positive review was 19 minutes ago as of writing this post. I hope Trustpilot do something from this. Or this will somehow damage their reputation as a review site. Regardless, a wise man can identify the difference between real and fake reviews.
To be fair, there is little Trustpilot can do about it.
They could delete and ban 1xbit from their webpage, however this may lead to more disinformation, it would one less place for people to also express their negative reviews.
And considering the mountains of shilling their must be throwing in pages like Trustpilot, it is possible that moderators and staff of those webpages are not sure how to deal with it, I doubt they are getting paid enough to manually remove what they consider to be shilling.
If I was hired by trustpilot to do basic maintenance on the webpage and suddenly I was told to manually remove shilled comments everyday I would eventually get fed up, unless I am getting a good salary from it.