In my experience, about 30-40% of the reviews I've seen are a mix between "axe to grind" and "I have no idea what I'm talking about". Some are extremely blatant

In my experience, about 30-40% of the reviews I've seen are a mix between "axe to grind" and "I have no idea what I'm talking about". Some are extremely blatant, such as reviewers "suggesting" you should cite a certain paper that isn't really related to your work. Others are very strict with the "this is just practical knowledge so it doesn't advance the science", and then there's the set of "I didn't understand the paper so I'm going to criticize it based on my misconceptions of it and reject it". I'm so glad to be out of that world, to be honest.