Because the Workers aren’t competing, they don’t give a shit. The Capitalists are competing for an even larger share of the pie. Instead of everyone cooperating, you fragment everyone into companies, which are like little factions.
Some factions doing well enough to create new kings like Bezos or Musk is also not a feature, given that there’s no democratic control.
Really not sure what you’re getting at. Why are you even on a platform rejecting Capitslism, rather than Reddit, if you’re so sure that leftism is a bad thing?