There might very well still have been something else bad. The discontent was there, if hitler hadn’t been the one to utilize it, it could’ve been someone else. Same with trump. There’s still a good chance that whoever would win the power struggle if the orange suddenly croaked had none of the apparent charisma of trump (not that I think he has any but it clearly works on a lot of people). Fascism is a personality cult, and just replacing that isn’t a given, but the initial rise heavily selects for someone who is able to create one. So if not them, it’d likely have been someone else maybe a little later.