Dialogue can indeed “tell.” Done occasionally, such telling can be a viable tool. Done too often, too blatantly, or in the ways you pointed out, dialogue that “tells” risks being an unnatural, unengaging info dump. A trick for informing readers via dialogue is to craft the chats so they seem to be about something other than the info being shared. In Scott Westerfeld’s Leviathan books, characters often speak of complex geopolitical plot points during cat-and-mouse exchanges, with the characters threatening each other, verbally jousting, and then, sometimes, forfeiting secrets. These discussions are as much about the characters’ constantly shifting power dynamics as the info being shared. In one info-heavy exchange, Westerfeld renders “telling” dialogue palatable by wrapping it in action: a man makes a boy explain political alliances to him while they spar with sabers. The swordfighting makes the scene fun, but Westerfeld pushes the moment beyond info and action by turning the sparring into a lesson about reading enemies’ maneuverings in politics and in life. That’s “telling” well done.