When markets were controlled by a relative few who had almost all the hard currency -- e.g. in the 1890s -- large-scale capital investment was impossible for up-and-comers. Thus Ma Bell, Standard Oil et al. couldn't be challenged by people with better ideas. The end result was a loss of efficiency in the system as a whole, until the government broke them up.
Yep. In my transhumanist conferences, I call it "lowering the barrier to entry". This is what open source, MOOC, crodfunding or 3D printing do: they lower the barrier to entry, wich makes any dwarf a giant.
Of course, current giants don't like it, that's understandable (rent-based economy).