Perhaps the BEST B1G Forum anywhere, here at College Football Fan Site, CFB51!!!

https://www.usnews.com/education/best-colleges/articles/how-us-news-calculated-the-rankings

Graduation/Retention: 22.5%
Undergrad Academic Reputation: 22.5%
Faculty Resources: 20%
Student selectivity: 12.5%
Financial resources: 10%
Graduation rate performance: 7.5%
Alumni giving: 5%

So less than a quarter is based on the actual undergrad academic reputation.

Schools that are highly selective get a double boost. Highly selective schools not only take the best students available (12.5%), but those students are more likely to achieve both first-year retention and six-year graduation rate (22.5%).

Now, if a school outperforms its selectivity and achieves a higher graduation rate than predicted by its incoming student population, it can somewhat "catch up" with graduation rate performance (7.5%), but that's a MUCH smaller weight than the combined 35% for selectivity and outright retention/graduation rates.

https://www.thoughtco.com/comparison-of-the-big-ten-universities-786967

I've said before that Purdue--outside of engineering--is not particularly hard to get into. This bears that out, with a 56% admission rate compared to Northwestern (11%), Michigan (29%), and Minnesota (44%) and Maryland (48%). Then with 6-year graduation rates, you see Northwestern (94%), Michigan, (91%), Maryland (87%), while Purdue is down at 77%. Wisconsin, PSU, Illinois, and OSU somewhat outperform their admission rate with their graduation rates, but of those 4 schools, Illinois is the only one with a similar engineering reputation as Purdue. Those schools all have similar acceptance rates but higher graduation rates, and they're numbers 17-20 on the above list while Purdue is 22.

So the rankings are NOT based on how good of an education you receive at each institution. Which isn't to say that any of the schools on that list will give you a bad education. But it's to say that only 22.5% of the ranking is based on the actual undergrad academic reputation of the school, and 77.5% is based upon "other".

https://www.graduateshotline.com/ranks/
https://www.usnews.com/best-colleges/rankings/engineering-doctorate
https://www.timeshighereducation.com/world-university-rankings/2018/subject-ranking/engineering-and-IT#!/page/0/length/25/sort_by/rank/sort_order/asc/cols/stats
http://www.shanghairanking.com/ARWU2017.html

I'm not knocking Wisconsin, Badge...
Your first three ranks show Purdue as ahead of Wisconsin in engineering. Not by an enormous margin, of course, but ahead. It was 11th vs 16th, 8th (tie) vs 14th (tie) for doctorate, and 25th vs 40th worldwide.
Your last rank is overall, not limited to engineering, and Wisconsin is a ways ahead of Purdue. This suggests that Wisconsin's OVERALL ranking makes up for them being somewhat below in engineering. I'd also state that this final link, if you read methodology, has a lot more to do with graduate research than undergraduate education. Which is important, but is a completely different metric than quality of undergrad education.
And to my point, although Wisconsin is good but several places below Illinois/Purdue on the list, the other two, PSU and OSU, are farther down. Not bad, but still below.

I've worked several places where school (and honors, but not grades) mattered; more to the point, with several people involved in hiring who cared deeply about what school applicants attended. And I've worked with a lot of clients who viewed the world the same way. Yes, graduate programs mattered more, but in hiring for positions that required undergrad, but not graduate degrees, undergrad institution matters, too.

I've never liked it, but those biases definitely exist out there in the world.