It is a huge delusion. Its promise was to bring education to all those who couln't previously reach it, either geographically, financially or for for time reason (fulltime work and no time to actually attend lessons). Instead, it brought higher education to those who already had a formal education (see Udacity's OMS-CS) or by offering non-degree, informal "certificates" (edX's micro-masters and Coursera's certificate…
It depends who you want to get it from. The school where I studied law has offered online undergraduate and postgraduate law degrees for over a decade.