So, 1.04% of the adult population of the US makes minimum wage.
In your logic, why should we set national economic policy based on 1%?
From [1]: 1.8 million workers made the federal minimum wage or less. But that does not say how many people made less than $15 an hour, which is considered a living wage. According to the NELP in 2016, 42% of US workers make less than $15 per hour. Nearly half of US workers. [2]
So raising the minimum wage would support nearly half the US workforce to be able to, you know, live. I think setting economic policy with this in mind makes more sense than only considering what teenagers need.
[1] https://www.bls.gov/opub/reports/minimum-wage/2017/home.htm [2] https://raisetheminimumwage.com/fight-for-15/
Therefore 0.0230.580.78 = 0.0104, or just over 1% of adults earn minimum wage.