Married a Canadian:
Your argument from “before” is still moot.
Thank you for helping to make my point though. There are NO even playing fields here. Therefore, as there ALWAYS are with multilateral trade between countries, there exists some regulation involved with trade or any “free trade” between countries when there are economic differences. Many factors are considered in this regard. Even free trade is never totally free. You have to consider, currency differences, operational cost differences, etc. China dumps its cheap stuff on the open market and keeps its currency artificially low... so the rest of the world applies duty and taxes. Why is it so hard for you to comprehend? Even your own UAE market is protected in every corner of business, from your phone carriers censorship of Skype, to who is permitted building contracts instead of Aldar or whomever.
Regarding legacy carriers: Of course they were protected to a degree! Are you so shallow in your thinking that countries would not protect and further their own interests just as the UAE does? This is because each country is/are competing with each other. They all want to further themselves in the global industrial business world do they not? But at the same time we all need each other to a degree to do it. And it is each countries right to establish that degree.
Airlines, or at least NON STATE SUPPORTED airlines (unlike EK/EY) are incredibly expensive to maintain. Most countries cannot afford to have more than one if they have generous civil rights attached to the price tag. There are no monopoly's in any of your examples as many international carriers serve the markets to and from Canada and in all the countries you quoted.
Is there a monopoly in the UAE?