The problem is when countries dont develop the infrastructure to support the increasing populations.
Look closer to home in the UK. With the waves of Eastern european immigrants that came to the UK, the plans to build enough schools, health facilities, homes etc didn't take off. Govt didn't spend and private sector waited for prices to go sky high before building to vastly increase profits.
I suspect Canada has the same problems.
IDK what it's like for you, but at my doctors, if i want an appointment, i have to ring up on the day 8am and wait in a queue. once the appointments are gone, they're gone. They do this to make it appear like their waiting lists are smaller. Also if they just booked appointments days in advance, they wouldn't have the slots free to see the more urgent patients.