Its funny you mentioned a laundromat. I thought of that. My dad bought a laundromat in the early 1970s. It was mostly self service, but we did have an employee who did service laundry for people who worked. My job was to keep enough quarters painted with red enamel nail polish to identify the quarters used by our employee. It didn't go well. No one in our family has any mechanical repair abilities. The machines needed a lot of maintenance. He sold the place quickly. I understand the modern industrial machines are much more reliable.