LILBURN, Ga. — Matthew Southern, 35, who has intellectual and developmental disabilities, is able to stay out of an institution because health aides paid through a Medicaid program assist him and his roommate with ordinary tasks. But amid a worker shortage worsened by the pandemic, Southern’s father, Dan, has had to step in to fill in gaps in his son’s care by volunteering at their home 45 minutes away from his northwestern Atlanta suburb. He blames the low pay across the industry. “No one wants to work for $12 an hour,” Dan Southern said. “People can work at Burger King and make more money.” …