Oh yes there are regulatory impediments in those two sectors that close access to the market.You can explain the lack of foreign investment in Canadian telecom and banking anyway you want. Perhaps, it's just a market overlooked by larger American, European and Japanese telecoms and banks. Rather I think there are regulatory impediments that close access to the market. I wasn't the first one to point it out on this thread.
The banking industry regulations have ensure stability in that sector, via tighter capital requirements
Given what occurred in the USA in 2008 most Canadians would agree there are justifications for maintaining stability there.
Trump wont agree
The telecom sector / Media is also regulated and the rational is a little more murky.
Sum it up as part of our "we like you guys , but do not want to be Americans" view on life
there are also rules about servicing Quebec in French and servicing the far north
I am not sure American companies would want to take on those service requirements
Canada is very likely to stand its ground on these two industries
The French issue would be a real hornets nest to kick.