I'm looking for specific and non obvious answers. Give me something visceral, rid the world of a figure or nation you hate. Preserve a culture you adore. It doesn't have to make sense either, you are basically god here.
What I mean is don't just say you'd get rid of imperialism or colonialism bc no shit
Personally I would make it so that the Americas are never discovered by the old world and every "would be" conquistador (especially cortez and pizarro) explodes.
But there'd be no logical reason to travel that far for some savage barbarians.
There wasn't really all that logical a reason to do the voyages at all beyond showing everyone how cool and rich and powerful the Ming emperors were. But most of Africa, all of Europe, and the Americas didn't get to see it.