Why hasn't magic supplanted technology or vice versa in your setting?

An obvious one would be that magic is a jack of all trades but master of none, and tech is better at its specific given task e.g that an airplane is faster than a flying spell.

Magic in my hard scifi setting is actually corundum nanotech, so I've accounted for the obvious thermodynamic limitations of such tiny machines. Magic also glows because the machines exchange data/energy via visible light due to being smaller than radio waves.