Open admission is an interesting way to do things. I spent a bit of time in Belgium where the main universities will accept anyone who has a high-school level education. The first year dropout rate can be 70% in some courses. This system seemed to be very well loved by Belgians.
https://www.oecd-ilibrary.org/docserver/eag_highlights-2010-...
Notably the US has the lowest dropout rate, so obviously they are pre-filtering students hard. That necessarily means that there are lots of people who /could/ have succeeded but were excluded at the admissions stage. The degree to which that's the right choice probably depends on whether you think doing a year of university and then leaving is a huge waste, a horrible failure, or a worthwhile experiment.
(The unique economics of US universities obviously interact with this calculus in pretty major ways.)
