Booking.com reported net income of 4.2 billion in 2023. More than American Airlines ($822 million), United ($2.6 billion) and almost as much as Delta (4.6 billion). Meanwhile Booking.com has no planes, no hotels, no rental cars, no inventory of anything, really.

https://www.nasdaq.com/market-activity/stocks/bkng/financial...

https://news.aa.com/news/news-details/2024/American-Airlines...

https://www.macrotrends.net/stocks/charts/UAL/united-airline....

https://finance.yahoo.com/news/delta-air-lines-full-2023-103...

Almost entirely from hotel reservations. The flight business is a small slice of that.

Agreed, but there are more major hotel chains than major airlines, for the purposes of providing a basic comparison. And this particular article was about them and Ryanair.