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.
It's all depends on your location, the country you are coming from and the kind of work you do. Things are very different from country to country, what is obtainable in your country could be something totally different in another country. Some people are not sure that they are residing in one state or country or location for more than 2 years. They keep traveling and moving from one state to another till the retire, that kind of person is not supposed to build a house until they are retired. Some people do not bother to leave properties for their children if they die because the government has a way to take care of everyone. In your country people live properties for their children and it appears that it is something that is compulsory and that is why you will advise everyone that has money to build even if and the long run they are losing because it will be an access to their children unborn. In conclusion I think this decision just fit well in the country you are and the amount they pay for rent and the amount that could be used to build a house.