Corporations do do central planning, but they do so at the high risk of becoming unmanageable and then they fall, and a competitor replaces them. Government central planning just raises taxes to cover the inefficiencies, until eventually the economy collapses.
Even regarding the scale of the organisation, there is lots of overlap between governments — at all levels, from countries, through states, to incorporated municipal governments — and businesses. You could reasonably compare Foxconn to Iceland or Wyoming (I would also list a US city, but https://en.wikipedia.org/wiki/List_of_cities_by_GDP gives me a lot of US Metropolitan Statistical Areas rather than cities, that seems like it would extend beyond the bit with the tax collection rules?)
