I would say it's never too old! However, I would also ask if you're at retirement age, how would you expect a 20-30 year old genetic women to respond to you flirting with her or asking her out on date? Same question for a 20-30 year old genetic escort? In my personal life I date trans and genetic women who are usually around 35 - 55. Or another way to say it, from 20 years younger than me to my own age. Its not at all about the sex or what kind of shape they're in or I'm in. It's the emotional, mental, social and life experiences that we can usually connect with.
I'm not sure of the age difference between you and the girls you're referring to, but while age has nothing to do wit hit, I believe that might. The majority of the trans escorts I see aren't more than 20 years younger, I like the MILF category. The times I do engage one that's more than that much younger than me, even if the sex is great, there usually isn't as good of a connection. I've accepted it could be that they find me too old for them and left it at that.
Every time clients think this "Hobby" is like buying a Ferrari or any luxury item an expensive dinner or something where you expect a certain level of respect, quality and top level service, remember IT'S NOT LIKE THAT! Think back to when this profession began up to today, there's always been escorts (girls, guys, trans) that personal will not do something regardless of money. They don't do anal, they don't do BBBJ, they don't do black people, or they don't do while people, or another ethnicity, they don't do handicapped people, they don't do fat people, and yes they don't do old people. How often do they really say those things upfront.
You're never too old for anything. Keep in mind you may be considered too old for some people, simply move on to other people that don't consider age that way....