Study by J.J. Prescott et al. on noncompetes in the US labor force is quoted in Washington Post
"Even janitors have noncompetes now. Nobody is safe." - Washington Post. 10/18/2018.
According to Evan Starr, J.J. Prescott and Norman Bishara, noncompetes cover 18 percent of all US workers. While it's true that they are still more prevalent among high-wage workers, noncompetes do cover 14 percent of workers without college degrees.