I will grant that sometimes a picture doesnt do justice to the person and there are many people that look a lot better in person. But if the person looks ok on the photo you know they will look at least that good in person.
Its not fair to a guy or girl who specifically wants someone attractive, and then they go on a date with someone described as “very pretty” and he or she is as plain looking as it gets. You really cant trust what people say as most people are reluctant to say the truth about looks or just assume that you “might” find that “look” attractive.