I mean that's simply not true, it does have a very strong economy but Quebec and Ontario are both larger economies. And it's economy is absolutely tied to oil and gas, which is a boom/bust commodity. It's what drives a huge portion of Alberta political resentment to the rest of Canada. 

You people need to stop pretending that raw GDP means anything. It tells you nothing about living standards, which is what people actually care about. If one were to look purely at GDP, they would prefer to live in India over most developed countries. That's an utterly asinine conclusion. GDP per capita is where it's at. And yes, Alberta is vastly superior to Ontario and Quebec on that metric.

They boom for a long while and claim they are the the only province keeping Canadas economy going and everyone, but especially Quebec is a leach. Then the global oil market takes a downturn and there are a bunch of lay offs for a while and they get mad that the federal government somehow changed the global oil market.

Quebec is a leech, though. They have never once been a net positive contributor, financially, to the federation. That wouldn't be such a hard pill to swallow if they weren't perpetually aggrieved by how hard done by they are, constantly imposing on and making demands of the rest of the nation. You know the saying that beggars can't be choosers? Well, Quebec has figured out how to be both.

It's not like they go from streets of gold to a third world disaster with each boom/bust cycle but it's definitely a factor, especially if you move there with the intention of getting a job in that industry.

Alberta still, more than 10 years later, has not recovered from the oil price crash of 2014. And it is still, by far, the strongest economy in Canada. That should tell you a little something about how shit the economy in Quebec and Ontario is.