Even ignoring that there just are going to be a lot more 300 person companies than 50,000 person companies, I'm not sure we actually need that many 50,000 person companies.
I personally think we're better off if businesses are large enough to operate reasonably efficiently at a single or small set of tasks/products, and no bigger. For one, you begin having weird things happen like a product being canceled or retired not because it was unprofitable to make, but because the company thought there were more profitable products they could be making. (Anyone remember HP's decision to stop making desktop computers?)
For another, you end up with a single point of failure with respect to management. With a hundred companies with a hundred CEOs, some of them of them will prosper and some of them will fail. If those hundred companies merge into a single company with a single CEO, the consequences of terrible management are now a hundred times worse.
I personally think we're better off if businesses are large enough to operate reasonably efficiently at a single or small set of tasks/products, and no bigger. For one, you begin having weird things happen like a product being canceled or retired not because it was unprofitable to make, but because the company thought there were more profitable products they could be making. (Anyone remember HP's decision to stop making desktop computers?)
For another, you end up with a single point of failure with respect to management. With a hundred companies with a hundred CEOs, some of them of them will prosper and some of them will fail. If those hundred companies merge into a single company with a single CEO, the consequences of terrible management are now a hundred times worse.