Why did nations usually choose to create republics after the fall of multiple empires after WWI?*

Because they want democracy.

Explanation:

Nations usually choose to create republics after the fall of multiple  empires after WWI because in republic, democracy type of government is present. The people did not want monarchy where one man made all the decision of the country while in democracy, representatives runs the country which were elected by the citizens of the country. So that's why nations choose republic instead of monarchy type of government.

in the declaration of independence, thomas jefferson announced that every human being has “certain unalienable rights,” among which are those to “life, liberty, and the pursuit of " hope i