How hard is it really to land MBB from M7 MBA? (U.S.)

I've heard everything from "everyone who really tries, gets it" to "not even HBS students are guaranteed".

Most recent data I could find is for class of 2020 (who would have received offers pre-COVID, so not an abnormal data set). Here are new MBB hires (not sponsored) as a % of total new consulting hires from that school:

1. GSB (95%)

2. HBS (93%)

3. Sloan (86%)

4. Wharton (78%)

5. Kellogg (70%)

6. Booth (68%)

7. Columbia (54%)

These numbers might not be perfectly accurate but let's assume they are directionally accurate.

So, my question is, how hard is it to be in the 50-80%? What differentiates the people who land MBB from the people who land T2? Do you see a lot people who network effectively, are fully prepared for cases, and strike out on all three firms? Any qualitative context you can add to these numbers would be helpful.

EDIT: Just realized, the above percentages would not reflect people who struck out on MBB and then took a non-consulting job, so you could argue they are overstated