Someone knowing your birthdate isn't really a big deal anyway

Social Security, dark web crackers, and crappy online forgotten passwords websites want to know your location. I jest. But seriously, DOB is extremely valuable, which is why I never use my real one online except for government stuff like that.

To the poster it sounded like he didn't want to hand that info over. I don't know the reason, I was just providing a fairly simple solution.

Also dob is frequently used as a verification. So it is kind of a big deal.

Maybe that's the point. It's not a very secure method of verification, so it is sensible to want something better, like an ad hoc secret phrase.

probably because it's cross referenced with your credit file, which they check when starting any post-paid plan.