The movie would've been decent if Sierra actually improved and all of the cringe-worthy moments were changed just a bit. Sierra did some horrible things through-out the movie and her "redemption arc" was literally a frickin' song. The song was cute, but it wasn't even an apology! It just turned into Sierra feeling bad for herself again, which is the main reason she will never improve. There was more character development for literally everyone else than Sierra Burgess, who was supposed to be the main character. She committed SEXUAL ASSAULT! If there was a genderbend, this entire movie would either not exist or would become the biggest scandal of the year. Sierra is a horrible and manipulative person and the other characters just forgive her because she's not a blonde bombshell and you should feel bad for her because of that. The actress isn't even ugly and the movie makes it her character's entire personality. Sierra's victim complex is based solely on the fact that she doesn't look like Angelina Jolie.
The dad quoting books could've been executed in a much less cringy way. The dad sounds like Noah Centineo's twitter posts. Also, in the beginning of the movie, Sierra had this "comeback" which was the lamest comeback I've ever heard. It seems like she learns a lot from her dad.