Airline junk fees, didn't know we had them.
When I book my flights, usually on Delta, there are different levels like First Class, Business Class, Enconomy Plus, Economy and another bargain low fee that doesn't allow you to pick your seat in advance.
If you want more space and more bennies or service pay more. There is nothing hidden at all. We go for Economy seat, not the bargain low fee one and because we fly a lot, we usually get upgraded to Economy Plus, which is a slightly better seat.
I remember when the Government regulated air travel in the 70s and air travel was significantly for expensive. Yes, you always got to check luggage, yes, everyone in economy (or tourist) was treated the same, because everyone paid the exact same price. Yes, that price adjusted for inflation would be way higher than we pay today.
I remember pricing a trip to Spain in 1970, economy flight from Atlanta to Madrid was about $450 pp. This was when the minimum wage was something like $1.25 per hour and my ex-wife as a school teacher made about $3000 per year. Same teacher today makes over 10 times that amount.