Why did the Western Roman Empire collapse under the onslaught of the barbarians and the Eastern Roman Empire survived?

The Western Roman Empire directly bordered on the barbarian world. In the 4th-5th century, there was an activation of barbarian tribes, the movement of which was provoked by the Great Migration of Nations. Constant clashes with barbarians on the borders, and then the invasion of the Huns completely undermined the power of the Western empire, which ultimately led to its death. The Eastern Empire was less subject to barbarian aggression. Here it is also necessary to take into account the factor that the lands of Byzantium were separated from Europe by the sea.