One of the ways in which the ACA has been good for the economy is something I don’t see discussed often enough: it freed some people from being tied to a job just for health insurance, allowing them to begin freelancing or start small businesses. When a worker is free to do that, two things happen. First, the job that person leaves becomes available for someone else to be hired. Second, if the newly free person starts a small business, they hire employees. This is how the ACA helps open up jobs and create jobs.
Medicare for all can extend this further. Freelancers might not make enough money to live on and also pay for health insurance under the ACA, but with Medicare for all, those people wouldn’t have to worry about that. More people would become free to leave jobs they only keep for health insurance.