I agree, Pacman doesn't have to prove himself again because he already carved his name in the boxing industry and have achieved a feat that will be hard for any boxer to attain.
That's why if he wants to fight again, there will be a lot of boxers that would be happy to fight against him. It is because of the fame that's attached to him and for those boxers, it's an honor to have a match against him.
What I can see with those new boxers that would still like to fight against him, it's like quick fame and career boost whether they'll be beaten or win against Pacman. That's what Ryan Garcia tried to do but Pacman didn't bite his words.
It is not just fame but also easy money for whoever will fight Manny Pacquiao. Though he is already old for boxing, his name still has a lot of pull for fans. I am sure, there are a lot of people who still want to see Pacquiao in the ring again. That alone can generate a lot of money. But I do not think we will still see Pacquaio in the ring again, either rank or exhibition.