Was Burt so old that he couldn't be fired?
Burt Cooper help found the agency and he was key in many early parts of the series, but after their next to last venture as a merged entity with another firm Burt didn't seem to be doing anything of relevance if at all other than filing his nails and kicking his feet up on the desk.
Was he really just there to lend prestige if the highest officers of any of their big clients like Chevy decided to tour the factory?