Why democracy is universally accepted by-most people of the world?

And where did you find that number? In fact the largest nation, China, has over a billion population and it's an autocracy...a Dictatorship, Xi is their dictator. After the dissolution of the Soviet Union, Russia became a democracy but with the rise of Putin it's slowly reverting back to the autocracy that it once was as the Soviet Union. Myanmar just underwent a coup where the military ousted the democratic government, so that democracy has become a military dictatorship. And democratic principles are being eroded in Venezuela under Maduro's socialist concepts. Even in the USA democracy is challenged by those who refuse to cede to the will of the people by fair voting and instead call the election a fraud even though there is no evidence to support that allegation.

My point...I reject your claim that "...most people..." accept democracy. In fact democracies are challenged around the globe daily by would be dictators and extremists.