One of my distant* relatives done that exact job many years ago, and most of the drivers were of that old enough to retire, but still had/wanted to work age.
From what I remember, it wasn’t exactly a hard job. Typical chauffeur job. Turn up on time, make sure the car is clean, be presentable, only talk when spoken to, and never hear anything that’s said in the vehicle. And spend a good part of your day sat around doing nothing.
*Husband of my mum’s cousin IIRC. You know, one of those relatives that only those who actually pay attention to the family tree, know the relationship.