Another avenue is doing regular screenings, orally or hand-written. Any sus answers, that student gets flagged and further evaluated.
But, the problem is, as I'm sure the article I haven't read points out, that cost-benefit is all fucked up. The benefit to students is they get a degree without having to do any work, so lots of people are going to do it, and the cost to Universities would be having to expel a good chunk of their students, which is going to cost them a lot of tuition money and alumni donations.
The reality is that the value of a university education--outside of STEM--in this bloated labor market is really just a social credit. What we need to tackle is all the poeple who can't get hired for positions they are absolutely qualified for but can't get because they don't have a degree.
There is something called a BONAFIDE QUALIFICATION written into employment law, and "college education" is considred a bonafide qualification even if it's not.