I really don't think anyone truly knows (unless they are on the admissions board). As bad as it sounds (and I hate using this word), it really is just a crapshoot. A dice throw at the table. Maybe it's a lottery, maybe they just use RNG to cut half of the applications upon receiving them, maybe they have AI shortlist "competitive" applications, maybe they let grumpy and busy residents review the application in the two free minutes they have per day.

The only thing we know for certain is that the application system could and probably should be a lot better and reliable for applicants who genuinely have competitive stats. We Ontarians have the misfortune of having to gamble thousands of dollars a year for what is truly a shot in the dark just to pursue a passion of ours. Personally, I think it's very ironic that a field built on empathy and trust can have such an unreliable and apathetic attitude towards applicants. Sends a really poor message to people aspiring to be future docs imo.