Why did the germanic barbarian tribes move into europe?

They move into the Empire from the east, pushed by other peoples behind them. They were initially settled in the Empire on the borders to help protect them from later arrivals.

Explanation:

Barbarian migrations and invasions: The wanderings of the Germanic peoples, which lasted until the early Middle Ages and destroyed the Western Roman Empire, were, together with the migrations of the Slavs, formative elements of the distribution of peoples in modern Europe.

answer; the best answer is (demand);

the technology changed agriculture in an impacting manner since many people left the field work by a cellular or other technological appliances