Parents (a group of people) who are trying to pass on life lessons to their children (the job-to-be-done) constitute a market.
Dental hygienists who clean patients’ teeth and farmers who grow a crop also constitute markets.
When defined in this way, there are tens of thousands of markets out there, and many of them have been around for decades —even centuries.
When it comes to getting a job done, people (job executors) don’t want to cobble a solution together from multiple, incompatible offerings. They want one solution that gets the whole job done. When you focus on the job-to-be-done, you are more likely to gradually evolve your products over time to get the entire job done and better satisfy your customers.