It’s not simply the transaction costs, though.
There is an economy of scale in being able to be multi-national when the differing laws of many nations create a production and consumption process that is cheaper to be multi-national than completely “in-house”. For example, the homesteading laws of some nation rich in raw materials, labor laws of India/China, import tariffs… Clearly, this is not free market activity.
Then there is the tax structure on stocks here. The most sensible arrangement would be to pay out dividends, and let investors choose whether to reinvest, diversify, or consume. Instead, most companies choose not to do this because dividends are double taxed as corporate income and as personal income. The least taxed option for corporate profit is reinvestment. From a tax standpoint, so long as a company is profitable (sometimes when it isn’t), it sees the most benefit in growth. Sometimes, growth merely means buying out a smaller, more efficient competitor.
Then there’s corporate welfare - subsidies, bail-outs, and gov’t loans, OH MY!
Then there’s the regulatory bodies who can create privilege without even knowing it (or do it corruptly) - I’d go through the agencies, but it’s too much alphabet soup. Some historic - ICC, FCC, DoAg. They can either limit the market by production caps, cost barriers, or direct prohibitions, but in most cases, big business sees less competition without facing as harsh costs.
Then there’s the monetary policy which redistributes wealth from non-investors to investors, encourages consumption or risky investment over simple saving, and creates countless “bigger fool” investment opportunities during artificial credit booms.
And…limited liability…