At what point, would you give up a seat for the elderly? At what point can you tell whether they’re old enough to have the seat you were sitting in?
Sure there are people with gray hair and slightly wrinkled skin. However, would it be an insult to say to the standing person in question, “Would you like my seat?”
Especially if it’s someone who obviously has gone through procedures of health and fitness. Or plastic surgery. All in the effort to look young. You look 50, but I know you’re 65+, have my seat.