To understand why cell phone cost more in Canada : As compared to US, Canada has a bigger land area 9.98 SqKM vs US 9..5sqKM with only a 10th in population. So the key here is a volume of people that the companies have to work with, in order to be profitable and adhere to government regulations to keep towers in towns where the population is in few hundreds. Our north is sparsely populated, but the telecom companies have to install a tower in every town to give Canadians services.
Having said that Australia is similar sized with (7.6SqKMs) and fewer population, and have one of the cheapest cellular plans. The only explanation here is competition. CRTC do not welcome more competition and hence prices are always high.
I think with 5G coming and more thirst for data, eventually Canadian telecoms would be forced to provide unlimited plans (just like how Home Internet is mostly unlimited now). It is inevitable and telecoms would start offering cheaper data.
5 years ago, unlimited calls was a premium plan feature, now it exists in the basic plans. I think this would be case with data as well.
Disclaimer: I used to work for TELECOM company.