Brevity is the best quality of some movies. A lot of movies now are over 2 hours while managing to be underdeveloped due to fluff and overdone/needless tangents (see, e.g., Monaco in The Last Jedi). Better development can be done efficiently, through tighter writing and more skillful directing. In Greatest Showman, for example, you could entirely eliminate Efron's character and use that time to make more of Barnum's internal growth.