I have calculated this would save between 50 and 150 human life-equivalents of time per year. You can see this calculation if you scroll to the bottom of the simulation page.

Sure, but it doesn’t add up to much useful time per person… Aggregate time saving across large numbers of people just seems like a fairly useless measure in general. To take it to an extreme, if you saved ten seconds in something everybody in the world does once or twice, you’d have saved a very large number of person years in aggregate but made basically no meaningful improvement to any individual’s life…

I’d think airlines would really want to put pax at the front that have tight connections (before or after). Unsure if any think this far ahead though.

But I also think they should put healthy 25 year olds in the emergency exit row for… emergencies, but they’d rather sell those seats to someone that’s often the poorest candidate to execute in an emergency.

Since planes rarely fall directly out of the sky, I wonder if there’s documented cases of “oh it’s an actual emergency” and people swapping seats.

You don't know that up front, e.g. if your plane is late and you need to hurry to a connecting flight.

Many people don't check baggage at all. This avoids extra fees, avoids waiting for checked baggage, and eliminates the possibility of lost baggage (assuming they don't make you gate check your carry on).

not everyone have checked bags. we only check our bags when going on long vacations, on majority of our flights we have only small bags.

For the airline, quicker deplaning means quicker turnaround, or a chance to give the plane a better clean-up before the next load of passenger shows up.

I almost never check a bag, everything I need fits in a ~35L duffel bag and 20L backpack. If I need prohibited or oversized tools or toys I ship it to my destination by UPS.

I also end up near the back of the plane all the time, because those are the available seats that don't have a higher price tag.

The delay is just a waste, but unfortunately the airlines aren't incentivized to make boarding or deplaning quick, they're trying to upcharge for more expensive seats. All the engineers are sitting at the gate for 15 minutes wondering why everyone's in a rush and paying extra to get "priority boarding" onto a cramped plane, then at the end of the flight, they're sitting in the back of the plane wondering why it takes 15 minutes for everyone to get off the plane, and how this wasteful process could be made more efficient.