In general, all the "use time machine to kill Hitler" ideas (in the rare cases they are not presented as just a joke) assume that it was Hitler the person and not the socioeconomic and historical conditions that resulted in the catastrophe. There were enough little Hitlers to fill that role. If you want to prevent anything beyond small details, you have your hands full of work as a time traveler.
I think this comment really understates just how effective Hitler was as a politician and a leader. He tried to forcibly take over the government and it failed. That part any "little Hitler" could do and also likely fail. What set him apart was his charisma and appeal to the downtrodden, not unlike a certain US politician. He was so well loved and respected that he was able to do heinous acts with near universal support. I don't think there are many people in history that can do that sort of thing as effectively as he did
But just as that certain other US politician, he mostly came to power due to complacency and collaboration by more moderate nationalists and conservatives. And while the mythos of Hitler was immense, his draw not to be underestimated, without people like Goebbels, without the people hungering for just about any populist figure that enabled their own conspiracy theories, he would have been just another charismatic figure.
Let's put it this way: If you went back in time and somehow turned Hitler into a communist would that have led to the KPD being voted into power by the enabling act? I seriously doubt it, he was an exceptionally skilled speaker and decent political tactician, but he was no hand that pulled the strings of fate on his own.
Go back in time and try to flag down Archduke Ferdinand's motor carriage only for the driver to get freaked out and go down the alternate route right to where Gavrilo was trying to get to the original route but was running late because another time traveler delayed him...
Personally, I'd think that would have resulted in a very different World War in the following years, but I am genuinely of the opinion that it was unavoidable. The conflicting imperialist interests were getting more and more tense, and Bismarck's web of alliances to keep the peace had not only already failed but had become impossible to maintain (due to those ever more rising tensions)