Personally I don’t think it’s ethical to ride someone young enough to be your child.
You are confusing ethical in relationships with ethical in business transactions - and this is a business transaction.
Would it be ethical for me to seek out someone to have a sexual relationship with who was the age that my granddaughter would be if I had children or grandchildren - no, it would be pretty weird in everyone’s eyes unless I was an actor or rock star.
But it isn’t a relationship, but a simple exchange of cash for services - and I assume there is no debate here on whether that is ethical or not!
Now sure if a girl is being trafficked and she has no choice who she has to service that is a problem, but then there are bigger issues at play.
However for a girl doing it out of choice to earn a higher income than working in a supermarket it’s their decision whether to accept the cash to suck and fuck the person in front of them if that person is old enough to be their father or grandfather.
And from the reaction of the younger girls I have seen they don’t seem to give a damn - money is money.