I'll admit, I didn't expect Great Ape Goku to defeated within a single chapter, and I agree that it felt a bit too quick, but I'll take too fast pacing over too slow pacing any day. They did convey pretty quickly how powerful the ape is, with destroying the trap room that nobody was really capable of denting outside of the Kamehameha, and throwing the building's top to stop the plane is classic monkey action.
As this clearly functions as the end of the arc (well, next chapter is the end according to the guide I find), I think what I find most interesting here is that Goku is positioned as the final conflict, and the tail weakness bit was more of a Chekhov's gun to our heroes winning than something to allow Goku to have conflict in his battles. It's quite nice seeing Yamcha and Puar get to be the heroes of the arc, as alluded to above the rest of the series doesn't treat them the best (the Z stuff doesn't for sure, I can't speak for the DB stuff much).