Kay signed with her first agent in 1984. In those 18 years before that she had done mostly regional theatre, work that never translated into work in New York. Directors I knew died, or became caterers. An actor might have been able to get a theatre job in the 70s, but even then, film and TV were closed to an actor without an agent. My first agent was terrific, but he soon left not only the agency, but also the business.
Agents shift jobs almost as quickly as actors.
Two of the three agents in my current office have changed in the last year. The people who replaced my first agent were not excited by me. So, after six years, I left without getting another agent first. She was freelancing again, but with no protection. Agents prefer to work with their signed clients first.