A changing means of production will likely shift the wealth from a previous ownership class to another. Whether that diffuses into the middle class is mostly a political problem. However the stronger a middle class is, (through access to capital) the faster technology production and adoption will become.
Or so is a school of thought of contemporary political economy (read Why Nations Fail by Daron Acemoglu. et. al. )
Example: the cotton gin did not make for a healthier middle class, since the political apparatus barred access to capital (and human rights and civic participation) for so much of the population.
This is nihilist thinking. There is no complete barring access to capital, even in the 19th century "middle class" loans were possible.
Today access to capital is as easy as it ever was (except maybe '06). The people who take risks are rewarded and there are countless stories of people moving out of middle class.
Or so is a school of thought of contemporary political economy (read Why Nations Fail by Daron Acemoglu. et. al. )
Example: the cotton gin did not make for a healthier middle class, since the political apparatus barred access to capital (and human rights and civic participation) for so much of the population.