Unbundling the value of the leg room and the value of the perks would reveal that people pay essentially nothing for those extra perks. It's not like if they ha

Unbundling the value of the leg room and the value of the perks would reveal that people pay essentially nothing for those extra perks. It's not like if they had a "leg" package and a "better food, priority boarding, etc." package, that the latter would be 50% of the premium and the former 50% of the premium, probably more like 90/10 (and notably, all of those other things cost essentially nothing for the airline to provide). They offer those perks as an enticement so travelers will feel like they are getting more stuff. Of course, you aren't even really paying for just more legroom. It's also used as price discrimination since invariably the Economy Plus seats are the last seats booked. So you are really paying for a combination of legroom and the flexibility to purchase your flight closer to the departure date. I don't even have an estimate on what would be the split if you could unbundle this fact, but eyeballing some flights in the next couple days between SFO and London or SFO and New York, all the economy seats on United are full but there are still 7-10 seats available in Economy Plus.