It would also be a pretty slippery slope to allow for foreign drivers licenses to be accepted for Canadian domestic travel. With the US, it might be easier, but I don’t think gate agents are really trained to know what drivers licenses look like for international travellers. Whereas they would generally know what a provincial drivers license looks like, and certainly what a passport looks like.
If I show up to the gate with a fake Nebraska ID, what are the odds that the GA would know what a real Nebraska ID looks like.
A huge number of assumptions there.... And you believe that's any different in the US, with, eg, an American Samoa DL? Hence the oft delayed push for "Real ID"