I think it’s easier for him to beat the one pokemon. That’s in the way of trainers succession than it is for him capturing a legendary by himself. Either than or he needed Rose’s help and Rose is a jerk.
Or the game decided to actually let the player take part in the story in the final act. And Leon losing to a legendary for story reasons is no different than Alder losing to a legendary for story reasons. At least it’s not forced down your throat that Alder is the undefeated champion.
No but Alder actually lost to a trainer before you could even fight him. Looks at N Not saying N is a good trainer or a compelling character because you beat N in the game multiple times. But I was hoping to beat Alder first. Then the game goes, nope.
I know that isn’t the case. Since you will be facing the Elite 4 at the end of the game with the Champion being the end of the game. Since Red/Blue made that very clear. And yes Blue was ahead of you throughout the game. Barry was ahead of you thoughout the game too til the last badge. That is why he showed up at the end.