Thanks for your thoughtful explanation. I certainly respect your opinion. I probably would characterize my opinion as "many movies" as opposed to your "nearly every movie".
I tried to think back to my favorite romantic comedies of all time and I agree that most clock in under 2 hours, but a few are definitely longer: Cukor's Romeo and Juliet, Capra's You Can't Take It with You, Wilder's Love in the Afternoon and The Apartment -- I'm 73 years old and pretty old school -- and the 2 Sex and the City films.
Regarding films of Broadway musicals, it's pretty hard to make a decent film version under 2 hours unless you cut a lot of the score. Most of the classic Broadway musical films of the past were over 2 hours: West Side Story, The Music Man, My Fair Lady, Oliver!, Fiddler on the Roof, Funny Girl to name a few.
The stage version of In the Heights was enjoyable, but pretty lumbering. Some of the story didn't make sense. The film streamlined the story and retained much of the score. I thought it was actually an improvement over the stage version. Its length didn't bother me, but again that's just IMO.