If you have a dog without purpose, you have an unhappy dog. The purpose can be as small as following you through the house and making sure you’re all right (not as a service dog, but as a companion), guarding the house, or as big as being a service dog, an agility competitor, or a fulltime guardian of sheep or other livestock.
Dogs aren’t as complex as humans. To them, work is work (even if it’s just sitting when asked), and work means they’re useful, which in turn means they’re wanted and needed by their human. Think of it this way- if someone never let you do anything, how would you feel? ‘No, go play, I can do the dishes.’ ‘No, go lie down, I can vacuum.’ For everything. I would love it at first, I admit it! But after a while I think I would become depressed to the point of despondency. What worth would I have?
When a dog has a job and a purpose, they carry themselves differently. They attack life with a rigor and listen for more instruction eagerly. Giving your dog purpose is giving them a better life, and that’s something we all strive to do.