Ideally yes, ppl shd have permanent address.
But everyone is not able to secure a job quickly and hence moving from airbnb to airbnb (upto 6-7 months).
For them UPS box is a life-saver because at-least OHIP is taken care of while struggle for job continues.
OHIP and driver's license has your home address for a reason. If you get hurt people need to find your family. The cost of staying in an airbnb is higher than rent.