1) They're still offering free if you go-it-alone 2) Their pedagogical approach is a bit different, with a great learn-do loop 3) Historically their content has been "ivy-worthy"

Quality of courses. Udacity offers very high quality courses, just like Coursera, not like University of Phoenix.

Some platforms will let anyone teach. Skillshare, for example. Which is fine - you get what you pay for, and occasionally you get lucky.

Coursera and Udacity classes are (all?) taught by faculty from name-brand universities. That doesn't guarantee a great experience, but it improves your odds.

As I understand it, it's pay to have a mentor and get a certificate. I think the courses are exactly the same as they were before, and just as free.