Right now, because of the health measures that are in place at airports, passengers have to stay on board the aircraft longer when they arrive at their destination. That certainly contributes to delays. It is also very difficult for the employees, because they have to deal with passengers' frustrations.
Delays are also due to a lack of staff at border services. It is estimated that before the pandemic, the screening process took 30 seconds per passenger, whereas it now takes five times that, from two to two and a half minutes.
As the interim president of the National Airlines Council of Canada mentioned, about 50,000 passengers arrive in Toronto every day, for example, and that number is expected to increase significantly this summer.