Taylor Swift: The Eras Tour is so dominant in theaters across the country that screenings of the Killers of the Flower Moon have had “Love Story” leaking in from next door during quiet moments. But the nearly three-hour-long Swift concert documentary is an intense theatrical experience in its own right, complete with singalongs, applause, and in some cases, young Swifties leaving their seats to stand, or dance, directly in front of the screen.