as someone who has lived in toronto with many friends in toronto, they don't buy houses. There are a couple scenarios:
1) parents give them money for down payment
2) move out of the city to Hamilton, Kitchener, etc etc for affordable real estate, which still is expensive
3) rent and STILL pay 50% or more of income to rent if trying to live alone...many of my non med school friends are still living with roommates paying 800-1000$ a month for a room in an apartment.
4) least likely is make own money by being in one of those very high income jobs and buy a house in to