A $ 15 increase in the minimum wage only increases the price level or otherwise leads to inflation. It does not increase your wellbeing and it certainly does not make you richer. Let me explain it in a simple scenario:
Imagine you’re a small business owner who hired 4 people and pays them $ 7.5 / hour each (the minimum wage varies depending on which state you are in). You have 2 suppliers who bring the materials into your company and their prices have stayed the same over a long period of time. You are also supplying products for another company that you have also had under contract for years.
Suddenly the government decides to raise the minimum wage to USD 15 / hour. As a business owner, you can no longer afford to have 5 employees. To reduce your losses, you will need to hire a few employees to get them the $ 15 hourly wage and keep going in business. You created two people who no longer even have an income.
It turns out that your supplier has the same problem. You either have to interpret people or raise prices. You decide to do both. They hired fewer percent of employees than you did, but raised the prices on their products, which are essential to your business. Now more people are unemployed and prices are higher. As a small business owner, you also have to deal with more expensive deliveries.
How are you? You can either lay out more people or increase your prices as well. But you know that your people are essential and that you cannot completely do the business yourself. So you decide to increase your prices too so you can keep making profits, staying in business and keeping your employees.
As you can see, the overall price level has increased, starting with your supplier, you, and whoever you do business with. But not everyone is a small business owner.
The people who were previously hired have to deal not only with their unemployment, but also with the increased price level. What they could previously buy for $ 5 now requires $ 8 or 9, which is a bigger chunk of their budget and moving them from poor to poorer.
Even those who stayed in the workforce have to pay higher prices for the products they buy. Your net income has stayed the same. The only thing that has really changed is the general price level, which is not a big deal for the rich but certainly for the poor!
The improvement in the economy is measured in terms of productivity, not the price level.