The relevant problem agencies face is that their products have a shelf life. If you're Tom Cruise's agent, why wouldn't you want to extend his career indefinitely?
Well if you’re Tom Cruise’s agent you get a commission for the work Tom Cruise does. Not his likeness.
That doesn’t sound right. To use a better example than Tom Cruise, I don’t think LeBron James negotiates his own sneaker deals. Some agent is getting a cut as usual.
If LeBron James dies and someone somehow has the rights to his likeness, they are not an agent however. They are the rights holder. Perhaps they coincidentally also have an agent doing the work, but it is not LeBron James’s agent. :)