Instead of a boss or firm now employing them they employ themselves. They are literally Self Employed. They do not own a business - they own a job. In fact they are the job - often even naming it after themselves. They focused on the wrong end Because most people are used to doing work they focused on their product or service and not on building a business to supply that product or service.
Most business people are too busy doing work to make any money.
Most business people are too busy doing work to build a business. Most business people are too busy doing work in the business to work on the business. These legs need to be in balance if your business is not to tip over. The most powerful tool for building a business is an organization chart. All businesses start and finish with the customer.