It's pretty common for people to stay in their summer cottages for a week or more, several times a summer. Renting a car for all that time gets very expensive, and it will be just sitting idle most of the time. At that point you may as well just buy a cheap used car for the same yearly cost.

The need for car ownership would plummet if we had self-driving cars that can autonomously drive back to the city, and to pick you up from the countryside.