Which is harder: Bowling a perfect game or getting a perfect 20?

I have friends who bowl frequently. They actually have their own ball, their own shoes and everything else. The other week I asked one of my friends which was harder in bowling: the perfect game or the perfect 20?

We all know the perfect game is essentially bowling 12 consecutive strikes. The perfect 20 is a concept I think about often but never see. The perfect 20 is a game in which the goal is to score 20 points. But in order to do that, you must knock down the 7-pin on the first roll of a frame, then follow it up by knocking down the 10-pin. That’s it. All 10 frames, you must do just that.

My buddy says the perfect 20 is harder. It makes sense. You have to bowl the ball 20 times compared to the 12 in the perfect game. Accuracy is much harder for it. But I still am not convinced. What do you think?