Statistically, yes. But based on where I fly, the reality is different. The last 6 flights I’ve been on have pushed back 10-15 minutes late because of how long it took for people to find a seat. The FA’s repeating over and over “This is a full flight and only middle seats are available. Please take the first available seat so we can push back on time.” And then the pilot once we are in the air “we got a bit of a late start but we can make up the time in the air.” The routes I fly are typically full, and popular for leisure tourists who may not be experienced travelers, or who are just entitled and think they can board last minute and get 3 seats together by making people move.