Same with books, there are also some anime’s that aren’t for everybody or in other words can’t be completely compared or comprehend. Every story has different beginning and ending it could be good to me and it could also be bad story for you. That being said I would pick Frieren over one piece because I preferred the story line. What Im trying to say is. Instead of saying “it’s better” say “IN MY OPINION it’s better”. You sound like you’re glorifying stories.