It used to not be that way, honestly. When I started playing, it appeared to me that dungeons were set up so that youd be forced to learn a mechanic or another. The solution to this issue might be looking at how syncing works. Most people who do roulette and get into the lower dungeons are drastically over geared/stated for the dungeon, relatively speaking. Meaning, when I started, people had a mixed bag of gear so that their iLvL wasnt always maxed out. Now, most everyone has a maxed out level of gear and makes clearing the dungeons pretty easy.
While I know its not a popular opinion, the oslution might be to sync it lower than the given level. So if its a level 40 dungeon, gear should be synced to 37 or 38. It's that or increase the difficulty of thsoe lower level dungeons to force actual consideration with what youre doing rather than just face rolling into the next aoe pack. That or start incorporating monsters that flat out punish AoE pulling a few rooms at a time and start forcing bosses to have kill mechanics that will wipe a tank or other person unless the mechanic is completed. Cause frankly, dungeons need to be harder to increase the player base's overall skill level. People complained non stop about how hard the burn was, and yet we're probably better for it cause it forced players to actually do something or die. Sometimes the devs should pull the playerbase into doing something, even if they kick and scream about it.