If there's an available cashier, I'll wait at her line.
And I do mean her. Don't think I've ever encountered a male cashier at any place that gives you the self-checkout option. So, yeah.... No, I'm not putting a young woman out of work who has morals. She could easily shake it at Ye Olde Gentleman's Club full of not-so-loveable scoundrels.
Or, it's an elderly woman who should have retired many years ago. But her children don't care about her. And, likely her husband died before she did. So can't count on financial support from him. She probably considers herself fortunate not to have been tossed and forgotten in some old folks home.
It's the same reason why, even though I EDC a lighter (Don't smoke, never have) I lie if a young man or woman comes up to me and asks if I have a light. Lost a good friend to Cancer. Not helping someone extremely slowly down that destination.