I don't understand why able-bodied/minded people remain in minimum wage jobs their entire life. And I made minimum wage myself working at a grocery store and vi

I don't understand why able-bodied/minded people remain in minimum wage jobs their entire life. And I made minimum wage myself working at a grocery store and video rental shop. The lady in the article was 60 in 2014. Why didn't she ever consider learning skills along the way that would offer salary growth or just flat out apply for higher paying jobs? I managed to raise my hourly wage from $5.15 to $27 over 6 years with only a high school diploma. And I was morbidly obese at the time too so it wasn't for my looks. We could at least push young minimum wage earners today toward learning a trade or other areas experiencing labor shortage like truckers, etc.