First-class cabins on commercial flights waste space and fuel that could be used to lower ticket prices for economy passengers, making air travel more accessible for everyone. A Boeing 747 could fit roughly 100 extra economy seats in the space taken by its 12 first-class suites, which are often empty on domestic routes. I've flown first class once on a free upgrade and honestly, the lie-flat seat isn't worth 5x the price — but that's a personal preference. Do premium tiers become indefensible when they contribute to the carbon footprint per passenger being up to 9 times higher?