People complaining about the length

Is this coming from an younger generation because I don’t understand why people are complaining about the length. So many of the greatest movies of all time are 3+ hours like Lawrence of Arabia, The Godfather, The Good, The Bad, and The Ugly, Schindler’s Lost, LOTR trilogy, Ben-Hur, Gone with the Wind and much much more. I rather have a complete movie and earn my money’s worth then some rushed crap. I feel like it has to be this younger generation who just don’t have long attention spans. This movie flew by and I honestly wished it was longer.