How do you figure? To take a related example, if you double the salary of teachers will you get students that are twice as smart from that?
When I was in college I got a job as an industrial electrician. Back in the late 80's the prevailing union wage for that job was around $16 an hour. I was making $15. The company (Keramont) didn't care when I was there only that everything worked and got installed on time. That meant I could work around my college classes. With the added GI bill to pay for college I was not a starving student by any means.
One of my high school friends worked there. He's a CEO of his own company today...
https://www.linkedin.com/in/anthony-mulligan-86b025b
I got hired because I could install and fix complex machinery, troubleshoot and repair machines that broke down, and could do it PDQ.
What you have today are burger flippers who think that they're worth $15 an hour or more for something anyone can be trained to do. They aren't. They don't deserve a "living wage." They deserve a wage commensurate with their skill that makes their employer's company profitable. If they don't like that, then they should get more skills and better job.