There's a scifi book I was reading a couple years ago that had this as a presence--models of people's personalities a la LLMs were a commodity, but they varied wildly in how accurate they were. Alphas were supposed to be 1-to-1 with the originating personality (to the point that they had legal protections? I can't remember), whereas gammas were used to menial things, like serving as a phone-menu style gatekeeper to the real person.

I can't for the life of me remember the name of the novel though... I'll have to go digging through my bookshelves later.

(Maybe Revelation Space, by Alistair Reynolds...?)