It just has oil. While it is nice having low taxes because of all the oil money, it can also be draining being surrounded by people who want to be annexed by Trump, or hold socially regressive views. But economically yes it's a great province.
Where are the tech giants or manufacturing giants? We have 1 tech giant who constantly criticizes Canada, 1 large manufacturer that gets bailed out twice a decade and otherwise we're just a country of housing schemes, financial services and fast food/retail.
Alberta real estate is affordable relative to the rest of Canada because it's actually not a good investment. Not that I think real estate should be treated as an investment, and this isn't a knock per se, but it's also nothing to brag about that every few years scores of people in Alberta are losing their shirts on real estate.
I'll probably buy a house next year in Edmonton for my daughter to use (and rent out) while she's at the UofA, but I fully expect to either lose money or not gain on it.
Contrast with Vancouver, which is hemmed in by ocean, mountains, and a border.
The standard unit in rural Alberta is the quarter section - 160 acres (half mile by half mile). Greater Edmonton is surrounded by mostly flat quarters in every direction as far as the eye can see.