A friend of mine got out of the military before we started working together. He is permanently partially disabled and most of the people he directly served with killed themselves because kicking down doors and shooting people is psychologically destructive.
Also present inductees will basically serve under a fascist dictator who wants to use the military to murder people.
That said the idea that poor people ought to move somewhere cheaper deserves attention.
1. Poor people who aren't literally homeless are the least mobile folks. They have difficulty moving in town because they can't come up with 3 months rent let alone money to move across the country and they are incredibly risk intolerant as they often can't afford for even one partner to be out of work for any length of time. Furthermore losing access to local resources might itself be calamitous. There is no replacing moms babysitting with paid for childcare.
2. Entanglements. People have connections, friendships, family, love interests. Without these people often fare worse.
3. Wages descend almost as fast as rent, job opportunities go down faster and most everything else stays about the same. Nobody invests 5000 and risks becoming a hobo in hopes of netting 150 a month in another minimim wage job in a shittier City.
4. Low wage jobs are in fact done by all sorts of people in all sorts of stages of their life and cities depend on those people to function. It's not clear how any tier one city should continue to function after all the people who should not be there leave
5. The idea hardly scales. People live where the jobs are now and those places are only cheaper now because they lack those economic opportunities.
The advice is not grounded in logic.