Compare it to the first Avengers. That one was 143 minutes. Age of Ultron is actually two minutes shorter. Two minutes! That’s like blinking twice. But the sequel feels denser. More characters. More explosions. More Quicksilver running in slow motion.
Then there’s Infinity War (149 minutes) and Endgame (a whopping 181 minutes). So Age of Ultron is the average Joe of the Avengers movies. Not too long. Not too short. Just… comfortable.