Both Capitalism and Socialism have room for public and private ownership, the difference is which sector controls the state, large firms, and key industries. The Nordic Countries are dominated by Private Capital, ie it is Capitalist, while the PRC is dominated by Public Ownership, ie it is Socialist.
Communism limits the personal freedoms of the bourgeoisie. All Communism is, is a more developed and global form of Socialism, where the small firms that once were private have all grown into the public sector or collapsed.
Karl Marx was never “in charge.” He developed a framework for analyzing Political Economy in a manner useful for the Proletariat to identify the manner in which we are exploited, and how we may go about defeating the Bourgeoisie. There are no rich oligarchs replacing Marx.
Belief systems certainly can be exploited, but that isn’t the point you are making here. Your point is that we should disregard analysis of Political Economy in favor of vibes-based action. If you don’t do the effort of studying Political Economy, any conclusions you come to will be based on shaky foundations, rather than throwing theory aside, we need to weild it to guide correct practice.
Funny enough, Mao described your error over half a century ago, in On Practice: