Are conferences an inefficient/​terrible discussion forum (in addition to academic papers)?

I’m asking this as a follow-up to http://​​lesswrong.com/​​lw/​​d5y/​​why_academic_papers_are_a_terrible_discussion/​​, which was written a few years ago, and which I find very interesting.

Many of the arguments advanced in http://​​lesswrong.com/​​lw/​​d5y/​​why_academic_papers_are_a_terrible_discussion/​​ (especially inaccessibility) could just as well apply to conferences, too.

I’d also wonder—would you consider conferences to also be a terrible discussion forum? What do you think would be some good alternatives?

The audience for conferences is limited, and people seem to remember only a tiny tiny fraction of everything they’ve encountered in a conference. The ideas in conferences don’t seem to do much for building up platforms of public discussions around the new subjects that are often announced in conferences (rather than, say, on online platforms).

I suppose one could advance the argument that ideas often get brought up/​discussed at conferences that wouldn’t be conveniently discussed in any other medium (for now..). But is this mostly because people are too comfortable with what they’re been brought up with?