I have been following online training for better than 5 years now. I have experienced college level training from Coursera and EDx. Both specialize in bringing courses from universities to your home.
There are several platforms to get online training, the two biggest for university level training are EDx a not for profit, and Coursera a for profit. I have found that while EDx has some very fine courses, Harvard’s CS50 being the gold plates standard for online training, I got more use from Coursera.
For example, Rice had a good course on interactive python, University of Michigan had an excellent course for Python for Informatics and John Hopkins had a good course on R programming for big data.
While the courses I took just four years ago would be considered archaic and the pedagogy was amateurish compared to top courses today, they were much more effective than taking a course at the local community college.
I have taken courses from Udemy also. Udemy is a similar beast to Coursera. While Coursera provides a platform for University level education, Udemy provides a platform for trade level education. While you might find a course in Coursera for marine biology, in Udemy you might find a course on how to sail. (I am actually taking that one)
I mention these here because both are considering going public. Both are growing quickly, for example Udemy has gone from 1 million ARR to 100 million in 5 years.
While there have been some notable failures in this area, Udacity comes to mind, the business models and the training methods are evolving quickly.
There is also some significant competition. Khan Academy, which is free has the best pedagogy of all the online training. It is expanding quickly and is working on creating a valuable diploma of some sort. (Salmon Khan was working on this in 2018 or 2019, however Khan Academy has spent the last year just attempting to keep the servers running with the crush of new users due to Covid 19.)
So, while this is not something you can invest in today, when the IPO’s happen, do not be caught unawares as to the value, if any, of Udemy and Courrsera.