My brother had some Dragon Ball Z fighting game on Wii where many bosses were beatable and then the next scene shows you getting your ass handed to you.
The game didn’t make you lose. It just kind of ignored if you won for story purposes.
In Budokai Tenkaichi 3 you can end sagas real early if you're good enough. Like, if you stunlock Nappa to death as kid gohan before Goku arrives you get funny dialogue that's basically "Huh, I won."