$15 an hour is a disastrous idea.
The author is young and doesn’t realize that the repercussions of rapid change can take a decade to ripple through an economy. So, quotations and “studies” that show that negative effects don’t occur in the short term are offered as “proof”, when in fact they are meaningless. And the longer the trend to automation, the less obvious it’s connection to wage is.
Let the states and cities decide for themselves.