You asserted that this story was proof that the college admissions system, as a whole, is broken. But now you’re pointing to a lack of data to support that? That doesn’t seem reasonable, at all.
I’d be very surprised if the percentage of fraud in the college admissions system exceeded the percentage of fraud in the welfare or disability system, for no other reason that this costs too damn much for a large percentage of people to afford.
On the percentage of welfare fraud, at least the sources linked in Wikipedia seems to think that it is not in consequential. https://en.wikipedia.org/wiki/Welfare_fraud
For the record, I don’t think that means welfare and disability are broken. Again, some degree of fraud should be expected. Similarly, I don’t think this story (even if the numbers turn out to be 10 or even 100 times those reported to date) is clear-cut evidence that the college admissions system is systematically broken. That conclusion is only reached if you had an expectation that the process was 100% pristine.