Out of all interactions on Twitter I've witnessed, conversations comes to mind the least to describe them. It's either people screaming at each other which barely makes it past a scripted dialogue of replies, or it's somebody saying ABC and all their fans saying "wow, so smart/brave/true". I don't see any value in those, and they make up the super majority on twitter.
The "helping experts stay informed" part is true though, there are some small communities where it's used to provide easy methods to contact others. That's a small benefit compared to the giant damage it does to actual dialogue.
Twitter's default mode is a school yard brawl where you have plenty of "followers" egging the fighters on. That's a utility if you want to destroy a society, but important to society?