I don't think this is close to universal among rich and famous, although no doubt you are correct about some. For one thing there is a principal agent problem i

I don't think this is close to universal among rich and famous, although no doubt you are correct about some. For one thing there is a principal agent problem in giving this kind of personal service company control over all your comms. Big impersonal companies can be more relied on to treat everyone the same. Many famous people will just sign up under a pseudonym. Family offices are also an artifact of generational wealth. Plenty of famous people aren't rich enough for something that heavily staffed. Also newly wealthy will often want to be able to deal with existing friends and family on the same basis as before. Indirectly, I've been able to observe some of the habits of someone with stratospheric levels of wealth. They had a phone number, but changed it frequently.