https://www.zippia.com/advice/business-travel-statistics/
and selling miles to credit card companies.
https://airlinegeeks.com/2021/12/17/here-s-why-airline-loyal...
If main cabin dropped by half, they would still fly the routes.
No, it's not. Where they make their money is completely orthogonal to how demand for flights is generated.
All passengers generate flight demand, so yes, they are just as responsible for CO2 emissions as the airline (you can argue about the proportions and degrees, but they still are) The airline is additionally responsible by not pricing in externality costs of CO2 emissions.
When I fly personally, I’m much more price sensitive than when I’m booking travel in the travel portal for my trillion dollar market cap employer who is flying me out to see a client to work on a deal. I’ve flown out with a couple of days notice plenty of times at prices I would never pay personally. If every single none business traveler stopped flying from SEA, I can guarantee you that they wouldn’t cut flights drastically.
There is a reason that the SEA airport has a special line for check in for Amazon and Microsoft.