There are currently 56.7 million freelancers in America, an increase of 3.7 million since 2017, according to a new report from Freelancers Union and Upwork. Flexibility and the freedom to work and live wherever they choose are the main reasons. But freelancers should beware: Not all cities are "freelancer-friendly." Here are some of the best — and worst — cities for those who wish to work remotely.