I don't think your premise is right. University degrees are not only for certification and reputation. Your specific example of medical practitioners alone goes

I don't think your premise is right. University degrees are not only for certification and reputation. Your specific example of medical practitioners alone goes against it. There is no other practical way for people to learn to practice medicine than in university. You can't really pick it up on your own in your spare time, unlike CS. As well as being an opportunity for someone to have time and freedom to study for a period of years university also provides a safe world to learn other soft skills and grow as a person. It's not prerequiste to develop those, of course, but it really helps.