Why is this surprising?
Academic success is important for a number of jobs. Academic success is necessary for entry to top universities and not for some others.......therefore, institution attended is a good, blunt instrument for filtering candidates. Isn't it common sense?
For jobs where there are huge numbers of applicants, they cannot read every application in detail or interview everyone, so they have to filter. This is an entirely sensible way to do it for certain jobs.
Arguing against this is like saying Unis shouldn't look at A Level predictions or results when making offers and offer absolutely regardless of those. Bearing in mind academic success at A Level is a good indicator of success in a degree (hardly surprising) then it makes sense to offer on that basis.
For jobs given to uni graduates without work experience, which require academic ability, filtering on uni makes sense. Once candidates have some experience in the workplace, their experience as well as their uni and qualifications count. As they become much older, experience increasingly counts......but until you've got experience, uni attended is one of the few bits of info. Of course, in highly competitive jobs, those who get the experience are likely (and increasingly so) to be from good universities.
It's a lie to say a degree from anywhere is equally valid for highly competing jobs. And to be honest, it's hard to see why anyone would ever think it is.
Outside of the most competitive jobs, uni attended will be less important.