Why did the Annapolis Convention of 1786 fail to answer the needs of the US?

Answer 1

Aside from the fact that only 5 of the 13 states were represented (New Jersey, New York, Pennsylvania, Delaware, and Virginia), the delegates had not been authorized to seek more than a limited agreement on commercial trade. The representatives of 4 other states did not arrive on time for the meeting. The remaining 4 states were absent.

The final report recognized that a wider convention would be required to address the deficiencies of the Articles of Confederation, not the least of which was the requirement of unanimity (difficult if not impossible to achieve). That convention would be held in Philadelphia in 1787, and ultimately replaced the Articles with an entirely new framework, the US Constitution.