Original sentence: A case can be made that Marxism provides a good explanation many phenomena identified within societies, but the politics of the world has changed and Marxism is no longer the major social movement for liberation from oppression that it used to be, so it is argued that Marxism's conceptual apparatus has become less relevant
Edited sentence: A case can be made that Marxism explains many phenomena identified within societies, but the politics of the world has changed and Marxism is no longer the major social movement for liberation from oppression that it used to be, so it is argued that Marxism's conceptual apparatus has become less relevant