Is the CPA Exam really the hardest career exam?

Me, whos trying become an accountant, and my friend, whos trying to become a lawyer, started arguing about which major exams were harder. him thinking the bar and me, cpa.

Does anybody in this sub who've had career changes or have taken the other major exams (mcat, bar, pe, etc) know which one is harder? I know this might be hard to answer but I'm really curious to know which is harder because surely one must the hardest.