This issue has been raised for a long time by the industry.
I will quote from the 2016 Canada Transportation Act Review report, the Emerson Report:
Canada is unique among its competitors in charging onerous rents and taxes that undermine competitiveness. Airport rents, for example, can represent up to 30 percent of airport operating budgets....
This report follows analysis by a committee commissioned by the federal government. Airport rents are about $400 million. You can discuss this with our colleagues from the airport authorities who will be appearing before you later today.
These are fees that are being charged to the airport authorities to use the land when several billion dollars have already been paid. Canada is the only country in the world with such a structure, as far as we know.