There are labs that guarantee < 72-hour turnaround times for travel. It costs extra but hey, that's life. This pandemic has been around for a year now so if it was that important to travel, it's worth paying extra for the test.
Not every place in the world is going to have PCR tests with results in a 72 hour window. There are going to be lots of Canadians falling through the cracks.
The 30 minute tests are antigen tests. The 72 hour tests are PCR tests. Antigen tests can basically only detect the virus if you're currently contagious. PCR tests can detect the virus before and after you're contagious. Airlines typically require the 72 hour PCR tests.
