Reason #8: He remains the best announcer in wrestling.
Despite the fact that he's nearing sixty, Robert Downey Junior has as of yet not given up on the role of Iron Man (and for you nerds who want to say he might die in Endgame, well, he could still appear in flashbacks, so there.) Why does Mr. Downey Junior keep going back to the role? Because he feels he still performs at a high level, and can offer his cast-mates something to help the franchise grow.
Jim Ross is in much the same boat. Despite his age, Good Old JR believes that not only can he help AEW get off the ground, he can help it thrive. Jim Ross has been announcing for longer than many wrestling fans have been alive; He can build up a wrestler's character--in fact, he's genius at doing so--and sell an angle to the audience no matter how ludicrous or contrived.
In short, Jim Ross is still the best voice in wrestling today, and now fans can look forward to hearing that voice on AEW broadcasts.