The American workforce is at a crossroads. Digitization and automation have replaced millions of middle-class jobs, while wages have stagnated for many who remain employed. A lot of labor has become insecure, low-income freelance work. Yet there is reason for optimism on behalf of workers, as scholars and business leaders outlined in an MIT conference on Wednesday. Automation and artificial intelligence do not just replace jobs; they also create them. And many labor, education, and safety-net policies could help workers greatly as well. That was the outlook of many participants…