What's not the point? I think you seriously underestimate the quality of participants on reddit. As an example, across just two subreddits I can bump up against Andrei Alexandrescu, Martin Odersky, Walter Bright, the STL maintainer at Microsoft, and many other great programmers who are working on the languages and libraries that I might use. Also, often videos from a conference talk will be posted by the author, who will then respond to questions in the comments. Where else do I get this sort of interaction? If there is somewhere else, I'm certainly missing out on it.

Just the other day, a pointer to Knuth's Annual Christmas Tree Lecture [0] was shared. I wouldn't have found it as soon otherwise.

[0] https://www.youtube.com/watch?v=VW3vgJYYIok