To paraphrase Tom Lehrer [1]: education is like a sewer; what you get out of it depends on what you put into it. This is true regardless of the medium. Some people will get value out of distance learning, others won't, just as some people will get value out of in-person learning and others won't. The only difference is the cost. Distance learning can be provided for a lot less money, so you can afford to be less selective on who you provide it to, and so your failure rates are likely to be higher. This does not reflect at all on the actual effectiveness of the process.

[EDIT] Reference added, because today's youth are apparently not well-versed in the classics:

[1] https://youtu.be/w8d0GwzY6cA?t=2210