I don't think that's true because customers cannot arbitrarily change industries and so even a very inefficient industry can be just as profitable as any other. As a shareholder you buy profitability, not efficiency.
Of course the likelihood of a more efficient competitor entering a market becomes higher the more inefficient the incumbents are. There are more than enough examples for that.
Of course the likelihood of a more efficient competitor entering a market becomes higher the more inefficient the incumbents are. There are more than enough examples for that.