That sounds... very abusable. What is the limit?
It's not abusable, if you need medical care then you need it. A doctor isn't going to do something to you or prescribe you medicine (which is also covered btw) unless you need it.
Canada isn't some barbaric ****hole where you're only allowed to need so much medical care until the government decides you're too sick to be allowed to live unless you're rich.
A lot of European countries and even Cuba have very similar systems as Canada, too.
My grandparents go to the US every summer, and before they do they make sure they have all kinda of crazy insurance just in case they get sick or hurt over there. That's how bad the US is. If it's more than a bandaid you're ****ed.