Taxing revenue would cause massive consolidation. Right now you might have a farmer sell their crop to a wholesaler, who then organizes it along with the output from other farmers and sells it on to the supermarket who in turn sells it to you. If you taxed revenues rather than profits, you'd end up taxing the total value of the goods 3 times rather than 1.
Ultimately, those companies would all merge or be bought out until they were one company to just pay taxes once.
Ultimately, those companies would all merge or be bought out until they were one company to just pay taxes once.