No, it’s a difference in business models. Low cost carriers approach things very differently. https://youtu.be/1-uNMj57Y4c
It’s not that their wasting this 15% of their unused seats airlines are simply more profitable with this pricing model.
“While you might expect the airlines to lower their prices a few days before the departure day to occupy the last seats, the opposite is true: Selling 20% of the remaining seats for $1,500 is more profitable than selling half of them for the regular fare of $550.” https://flightfox.com/tradecraft/how-do-airlines-set-prices
Further that’s a statistical average, they might not have any last minute travelers on flight X or they might sell out flight Y 1 hour before departure. As airlines can’t both raise and lower prices at the last minute they A reserve seats for the possibility and B frequency lose the gamble.
The hypothetical in that article would make more money if they sold 80 seats at $495, 15 seats at 900 and then 5 at $1500 (that makes $60,600). There are strong incentives here to fill the seats.
And they are doing the scalpers trick where someone desperate to get on the flight can. As opposed to when the good would be overbought and someone willing to pay $1,500 has to start paying off passengers for their booking instead of giving more money to the people who put planes in the sky.
Plus, if we're both running this strategy, I have huge incentives to offer $1,495 seats to steal your high paying customers off you. It just doesn't work as a strategy unless it is already impossible to fill the plane - which is quite likely the case.
If you designate say 75% of your ticks at a lower price of X then some people willing to pay more will just buy at that price. Essentially the trick is to minimize people who are willing to pay more who end up buying cheaper tickets. And it turns out people booking close to the flight are generally willing to pay more. Sure six months out they still sell off up to 75% of tickets at ~100$ raising or lowering prices based on demand so their losses are limited if nobody else buys the ticket the flight is still mostly full. But at that 75% they start the ramp up and they also ramp things up as the flight gets close.
2 weeks out they say all tickets are 200$ even if some of those 75% are unsold. At the last day bump it to 400$. If over 1 month we can ignore seats at 100$ because that’s unchanged. Sell 1,000 seats at 200$, and 500 seats at 400$ and fly with say 1500 empty seats that’s 400,000$ where you would only make 300,000$ if all 3,000 seats where sold for 100$. But what if they dropped prices at the last hour? Well most of the time they have empty seats so many would avoid the 400$ ticket and would tend to wait around for that window especially for flights from A to B leaving every hour. Peak prices are a game of chicken and they can’t blink or they lose billions in revenue.
This is of course heavily simplified but it does demonstrate the basic trick I am talking about where they extract value from unsold inventory.
I can tell you why the airlines would be planning on having empty seats in practice - because there are sometimes literally not enough people interested in travelling to fill the aircraft, so they adopt a strategy of leaving empty seats because they have no other option. If you've ever flown some god-awful connecting flight at 2am you might have seen that in action yourself. But that isn't because the airline is choosing to reserve seats, they'd much rather have more passengers - that just isn't an option.
How and or when exactly to you plan to sell those tickets?
Do it after the price hike and people will just wait.
Do it before and you need to see the future to know how many seats will eventually be sold otherwise you just traded a 400$ ticket for a 100$ ticket. It’s no more a viable option than suggesting it’s easy to win the lottery just pick the correct numbers.
Your strategy has the same problem - you have to predict how many last minute travellers there are too. If you just leave an unnecessary buffer then the strategy fails. The one of us who does a better job of putting exactly 100 bodies in 100 seats - none left over - is going to have a more profitable airline. That is somewhat core to the argument us pedant capitalists make.
It’s just the math works out so on the margin having even slightly better than a 1 in 4 chance of selling at 4x the prices is a net gain. Suppose their reserving 50 seats and have a 26% chance of selling all 50, only a 50% chance of selling 20 or more.
That means on 1/2 of flights their intentionally flying with 30 or more empty seats, but reserving even 49 seats rather than 50 loses them money.
85% capacity use of an asset is really quite high. If they managed to achieve mid-high 90s that would be startling given how good humans are at missing flights and changing plans.
To repeat myself, if the plan is to leave your capital unutilised for 15% of the time, on purpose, when there is an alternative, then the planner is a lousy capitalist and doomed to soon be a broke one.