Sharing your research profile actually does tell a lot. If you're familiar with the admission process you'll know this. For research programs, students are often assigned to a supervisor based on your research interest.
For example, if theres no professor conducting research in your area of interest or there aren't any openings for research in that area, you're almost rejected by default. (my friend was rejected for this, and in the admission status section one person said he was rejected for this in Waterloo some time in February)
Professors are given the profiles of competitive students within their area of interest, and they have to pick students from the pool. So if there are a lot of people applying for your area, the competition is more.
If for example you're the only applicant within your area of interest, and you meet all requirements and your profile is the only one forwarded to a certain professor, if he has opening in his group, you're selected by default.
So like I said, you aren't really competing against all applicants, just those with same interest as you.
Based on observations, majority of applicants are in for machine learning. So likely the most competitive.