Well certainly moving out in an earlier age makes you mature faster than your sit at home counter parts. There is a term for these Young adults living in with their parents to save money from rent and mortgages. I forgot what it called.

Anyways there are many reasons for these young adults to sit it at home.
One of the main reasons as I have stated above is the rent and mortgage of property Australia wide.

The properties which are located around facilities such as shopping complexes, public transports, libraries, universities and etc tend to be more expensive especially rent.

It will at least cost a person around $190AU - $220AU dollars per week to have a decent room around these facilities. The estimated prices I have stated are in the suburbs which is around 20 - 30 minutes drive from Sydney Center.

The price can vary according to the room size and the maintenance of the property. And it's really insane to live in areas at least 2 - 7 km from Sydney Central.

Rent pricing can go up to more than $320 - $ 500 a week. Anything less than that would be shared rooms or small single rooms that are badly maintained.

The highest pricing a rent can go would be $1500 a week. These usually would be modern luxury apartments in Sydney CBD.

Bearing this in mind they would tell themselves why should they waste their hard earned money paying $720 - $ 880 dollars a month and more while they can save that money by staying at home with their parents and spend it on a little leisure and entertainment such as going out to movies, pubs/clubs or eating out with friends.

Makes sense?

I think so with food pricing, products as well as oil going up I don't see why would they choose not to leave home.
However there is pros and cons about these young people staying at home.
But this matter would be discussed later.