It’s in that movie but it’s not from it. Did you seriously think it had never been said before that? It’s been used for centuries in different forms, even exactly as said in glass onion.

Same with “it’s so bad it’s good” both with and without “nah, it’s just bad” after. I think one of the most well known things like that is “The Room”, and many reference that movie when something else fits the description but it’s not at all from that movie, it existed long before it.