One, that has been pointed out already, is that companies are not hive minds. Doesn't matter how rich and powerful you are, you have to hire layers of managements to run your organization. These managers get their share of status, power & money by managing more people. The people they manage also want to get into management, so more layers and departments will be created. You are also competing with other companies to keep your employees happy so that they keep making you richer, and for this you have to give them their share. Bullshit jobs are a wealth (and status) redistribution mechanism that works almost as a force of nature under the current state of affairs.
The second thing is that if your plan worked (companies get rid of all bullshit jobs), then society would collapse. .001% of the people would end up with 99.999% of the wealth, everyone else in abject poverty. The more technology evolved, the more extreme this inequality would become. Of course society cannot work like this, and democracies force politicians to align themselves with the interest of the general public -- to some small degree perhaps, but enough here to create enough pressure for such jobs to keep existing.