In those days highways, railroads, and trucks did not exist
Like it was stated multiple times on this forum. The utility is CPEC is that it is the initial seed funding to kickstart growth and investment which was lagging in many sectors of the economy. In some ways it has worked. In many others way we will not know until 2030.
Much will depend if Pakistan is able to leverage the development. So far with the initial energy projects the results are there. Exports have increased. Energy production is at an all time high. Energy costs are up but right now there is significant global inflation.
Can this be leveraged to incentive China manufactering and eventually even other countries? of course.
I have no complaints here except the cost of the projects