This is an important question. I think there are many reasons why poverty is growing in Canada, which also leads to greater homelessness.
First, in an effort to stimulate the economy in Canada, the government has given tax breaks to companies. The hope is that these companies will hire more people and create more jobs. This has yet to be seen. The flip side of tax breaks is that there is less revenue for the government. This means that there are cuts to entitlements. So, people, who need more government assistance wind up getting poorer. In time, this poverty leads to homelessness.
Second, the world now is globally linked. This is to say that Canada's economy is connected to North America, Asia and Europe. So, as other parts of the world suffer, so will Canada to a certain degree. This will lead to greater poverty and homelessness in time.
Finally, I should say that Canada is better off than most Western countries.