It’s a monetary union with no common fiscal policies and no mechanism to correct disparity between members. Complete train wreck since it has been put in place.

Germany has been abusing it from the start running huge trade surplus, compressing salaries, using its excess savings to buy foreign debts instead of investing and being shielded from monetary appreciation by the consumption and investments of other countries. The euro is basically Germany robbing blind the other members while pretending to be virtuous and blocking most of what could have improved the situation.