I think that reviews should be as factual as possible, and meant both for the writer (to know what they did well or wrong) and for the readers (to know what is objectively good or bad in the book). Sure, you can say I loved xyz, but ultimately, it doesn't hold any value. Meanwhile, something like "the pacing was rather slow" or "the lore was well explained but not overwhelming" are objective statements, or tend to be objective, and to me, it'd help so much more to just be factual in reviews