Only profits are taxed, and they're only vaguely related to revenue, and both profit and revenue are vaguely related to whether a company is a monopoly or not. Profit is an okay-ish measure of how much a monopoly a company is, but not great. Comcast and Amazon turn profits of ~10 billion. Apple is 60 billion, microsoft is 16 billion. Amazon is much more of a monopoly than either of those, and Comcast enjoys a much stronger natural monopoly as well. The industries are just different sizes and the supply/demand curves are different, and for some reason people are just super willing to pay an absurd premium for Apple products.

A progressive corporate tax still makes some sense, and there's basically no excuse for their taxes being less simple than a citizen's. However active management is still required. Markets are fast and efficient but they are often dumb.