Welcome to FT! RBC spells out quite clearly in the program terms that taxes, fees, and surcharges are the responsibility of the traveler. RBC does not set these exorbitant amounts you’re seeing, nor do governments... it’s mostly the airlines. More and more, airlines are choosing to break out a fuel surcharge separately from the base fare. So instead of an $800 base fare, they might have a $250 base fare and a $550 fuel surcharge. Both ultimately total $800 but the distinction matters with the Avion program - they’d effectively cover the entire thing if airlines priced the ticket the first way, but they’ll only cover the $250 when the airlines price the ticket the second way.

If you want to book with Avion points, all you can do is look for airlines that don’t break out the fuel surcharge separately, so that RBC will cover more of the cost. I don’t know which airlines do and which don’t, or if there are even any left that don’t. The upshot of booking this way is that you can book any flight you want... you don’t need to worry about award availability which is often capacity controlled, especially to popular destinations at popular times. You should be able to book business class and simply pay the amount beyond the $ limit for the award.

If you opt to transfer the points to Avios, be aware that you may not be escaping fuel surcharges. Before you transfer, register an account at ba.com to search for award travel and see 1) if availability even exists, 2) how many Avios are required, and 3) how bad the taxes and fees are.

I’m not familiar with WestJet’s program so cannot offer advice there.