I don’t know that niche manipulates reviews. With that said, I don’t place much value in these crowd-sourced ratings which also use unverified data. And if you look at the # of reviews relative to the #of kids who have attended over those years, you know you are getting only a tiny percentage of the story.
I would recommend that you read reviews and based on them, figure out what you’d like to dig into a bit more. For example, if lots of kids at a school talk about knowing their profs well, etc., you can probably know that the classroom experience will be “personal”. If Greek life comes up around social life, you might want to know what people outside that do for fun. If kids talk about doing a lot in the city nearby, you may want to know what kind of budget you’d need for that.
Iow, use it not for the answers but to figure out which questions to ask.