How did utopian societies fail?

Answer 1

many did not have a way to consistently make money and everyone's definition of what a utopia should be is different (some utopia's thought reproducing was a sin...)

Answer 2

Utopian societies often failed due to unrealistic expectations, internal conflicts, lack of individual freedoms, and economic challenges. The strict rules and regulations imposed by leaders, as well as the difficulties in sustaining communal living and harmony among members, also contributed to their downfall.