Or you can't? Because I've always thought that would have saved a crap load of trouble if Goku would have just wish for omnipotence, and end the show very early lol!
Or a villain thought of that wish instead of immortality since omnipotence comes with eternal life.
Excuse me if I missed or forgot something that prevents that wish. But also would that depend on which Dragonballs you use like the Namek or Black Stars?