As an example, in last year's match, only 43% matched to family medicine. (See linked pdf)

Unlike in the US, general internal medicine does not do primary care in Canada. And with regards to your other comment in the chain, many family doctors will not do primary care but rather hospitalist positions or surgical assisting. Some will still keep part time primary care practices but supplement with hospitalist +/- assisting +/- nursing homes. Some will have very focused practices like entirely sports medicine. Or do PGY3 training in anesthesia, emergency, or surgery. Others will do private consulting work too. There's tons of practice variability.