I've seen plenty with low scores.
One uses them as a possible source of info, but best if backed up by others sources. After all, what else would you substitute.
I do not bother looking
however after a visit to pontins in southport then i did start looking at trip advisor wish I had before I went ( what a shet hole)
Yes, I believe them. We were going to eat out on Christmas Day and took to Trust Pilot to see what others said about the place - glad I did, there were so many bad reviews all with similar complaints that we decided not to go !
I gave a bad review once and I was advised in strong terms by the company I was reviewing to either remove or update.
I removed as it wasn't worth the hassle I was getting, but put my views elsewhere.