The united States under the Articles was not effectively governed - that's exactly why the Articles were replaced by the Constitution.
There was no national economy - or a currency that was uniform throughout the land. America was, and still is, a land of trade. It was curtailed because of no uniformity in exchange.
There was no equal recourse to justice - a famous early case is about the farmer in Pennsylvania whose geese could not be marketed effectively in Maryland, just a few miles away, because there was a state import duty.
There was no method of agreement on development of new territories, or of improvements in transportation and communication.
There was no equality in legislation - each state, no matter how large or small in wealth and population, had the same vote in the national legislature.
The system broke down because there was little incentive to make it work.