According to Common Sense, Britain could not effectively rule the American colonies because there were big differences in religion.
the colonies were too large and far away.
the British navy could not protect them.
Britain had too few resources.

the colonies were too large and far away.

Explanation:

The common sense a pamphlet written by Thomas Paine which created to convinced people to support the independence movement from the British Empire.

In the common sense, Paine argued that the size of American territory and the distance between America and Britain make it impossible for Britain to rule America in the efficient manner. (at that time, modern means of communication such as telephone hasn't been invented)

Because of this, Paine argued that the people of colony should take control of their own territory and managed the politic and economic aspect in the colonies by their own.