I think paying for water is a great opportunity. Maybe even the precious Biscoff. Especially for those cross country flights.

When I was young there was a discount airline named People Express that actually operated like this. In retrospect I imagine a lot of their nickel & diming would be considered standard these days, but back then it was revolutionary in both good & bad ways.

You’re way late to that party, Ryanair used to charge crew for water.

Spirit Airlines does not give free water. They will give you a cup of ice if you ask.