Was the black death a tipping point towards modern society?
Without an initial labor shortage, there is no incentive to mechanize and automate (and muscle-power can only go so far up the technological tree).

Magical healing could prevent the pandemics that triggered the earliest industrial revolutions. (and without a railroad, there is no large scale coal mining or iron production ... and, therefore, no industrial age to free farmers and craftsmen up for more advanced technologies.)