Imagine China as a company. There is a board of directors, and Xi is the head of that board. The board runs a lot of lower ranking boards that control all the aspects of government operation.

Have a problem with your plumbing? Go to your local province or city board. A whole region experiencing drought? The regional board has an action plan that they impose on the local boards to implement with government regional help. Xi is responsible for steering the overarching policy of China moving forward as a country. His role is to say “make China control the South China Sea and receive deference from those countries” to the military, and then it’s their problem to figure out how to harass shipping.

You get promoted to higher boards for good work, and the board votes for its leader. Read Xi’s promotion history. I would die after that many years of office politics, myself.