This is just manners I learned at home. Me personally, even though I’m not wealthy but relatively well-off, I would be happy to do this for a friend. None of my friends would expect this from me but would make it obvious ahead of time they’re broke or just flat out would tell me that we should do something else. IMO, If your friends are expecting you to just pay for their shit all the time, you might need new friends that like you for you and not your money. I have had friends in the past that liked me for what I have and those bridges are long since burnt.