Oh sure there have been PLENTY of "what if there was no WWII?" or "What if there was no nazi Germany?" But WWII was BIG. It was something that had a lot of built up 'angst' about it...
SO let us say that, oh, perhaps Hitlers painting career gets off the ground. Some rich merchant is impressed, and hires Hitler to paint just for him in some other country. Hitler never goes to war, never writes 'Mein Kampf', the Nazi's soon have no charismatic leader to rally behind, and Nazi Germany never happens. Germany languishes in an extended depression while Europe moves on.
But what of the rest of the Axis? Japan is still chomping at the bit to expand into Korea and China, and would still need to stop the US in the Pacfic in order to do so. And Mussolini is eager to expand down into Africa and much of the Mediterranean
So the question is, without a huge Germany industrial force pushing them on, do they even bother to still attack? Does Pearl Harbor still happen? Will the US still end up dropping nukes on Japan?