If you have the money buy the house and stop renting. Remember even though you are renting a house you have to do some maintenance work in the house to you taste and not everything you will like to involve your landlord to come and do it for you buy a house, you can design your house the way you want. There are some kind of things you won't do in the rented place but you can do it in your own house.
It is not even advisable for a grown up person to rent a house when he has the money. There is nothing like personal home.
I believe anyone who have the money and haven't have their own house yet will do that. It only needs a basic thinking. They know that they can save more and it gives them a peace of mind. They can also customize their house freely because it was their own.
Those who currently rent a house, they do this because they don't have a good budget yet but I'm sure that one of their dreams is also to own their own house. If we are renting, I think the maintenance for the house is already an obligation of the land lord/lady. AFAIK there is no rule if what age can rent or own a home but it only depends on our financial capabilities.