The British colonies in the United States also adopted the parliamentary system. Why not adopt the management mode of president's full authority?

Not all British colonies in the United States have adopted parliamentary system, and some of them have not yet been "autonomous". There are three ways of British rule in the United States: appointing a governor, handing it over to a company and local autonomy. And the governor's management model. Many American colonies were not built by the British government, but by British immigrants themselves, and the British government may not even know it. The British government's granting of "autonomy" to some colonies is only an ex post facto ratification. These colonies only "obey" the suzerain and are not "managed" by it. What kind of management mode the "autonomous" colonies choose is their own business, and some States will also elect their own "governors".