The problem is that, if everyone took your advice, who would pick up the garbage and make the lattes?

The other problem is that if you want to "better your life" and stop working at Amazon for $15/hr, historically you had to go somewhere where those better jobs are (often NYC/SF/LA, depending on industry). Maybe with remote work becoming more common this will change, but telling people to live in low CoL areas unless they're already making a good income puts a serious damper on social mobility.