This is unfortunately true. I would suggest Blizzard makes a mode that plays how most players play – which is huge pulling. I doubt they’ll do that, but they should. Otherwise not much is actually learned other than tank pathing, like you said. In fact, you can’t even learn mechanics because bosses die so fast in normal dungeons.
AI dungeons are a great direction for the game, but Blizzard needs to replicate how their content is actually played (mostly) in order for anyone to get any training from them. I would actually suggest raising AI dungeons to mythic if they won’t make a “fast pulls” mode.