Thing is that you won’t find many people living and working illegally in Canada. It’s so easy to stall your stay and get permanency from inside Canada than any country. If you are a student you have the option of CEC, PNP, if you are an illegal there’s the option of asylum. If you are denied asylum, you can apply for H&C and if it’s denied you can appeal in court and further stall your stay and so on.IRCC among other things, is held accountable for over-stayers or illegal workers. So, they try to sift such people.
Lastly, degree mills do get de-recognized as a DLI from time to time.
I doubt IRCC is actively looking for people to deport