COUGH - Brayflox Longstop - COUGH.Haukke Manor HM is the best example I can think of.
They certainly haven't given up on the idea, just limited it to chests being visibly a walk away - enough for a stray player to pick them up while their tank is being all 'must zerg and pick up three packs'. In comparison, places like Brayflox encourage the light exploration, seeing as saving goblins (essentially a sub-task) provides chests, while others are very well hidden in their own side-rooms that you are highly unlikely to go to during a clear. Decided to solo it about 8 times to gather the Battlemage Set for an alt (as well as re-do a Hunting log after a GC transfer) and it seems that you can save 3 Goblins (3 Chests + 1 for the first drake you kill after first boss), along with (can't remember if it's two or three) extra chests at the lake, and one (with a hidden Coerl that is tougher than the average trash) guarding a chest at the end which provides class-specific green-rings.
That's 3 guaranteed dungeon drops, 1 ring chest, and 6-7 regular chests (which have a chance of becoming silver chests). I have 1200'ish hours in this game and it was only at the weekend I noticed this, because every group during my levelling days were just chomping at the bit to complete it ASAP. Undersized, you can rush from A to B in about 6.40/7.20mins and snag quite a lot of 31-32 gear for alts (or just piledrive them into your Seal collection), and barely anyone made any effort to capitalize on this back in my day. Some of the later ones have optional rooms or hidden alcoves and crevices that hold chests, but the 9/10 liklihood is they'll be skipped. Don't get me wrong, when it comes to the lower dungeons, I don't want to spend all day max-clearing it, but adding some appeal (extra XP would be an example incentive for, say, mapping a dungeon per visit [preferably without 20 tonnes of trash in the way]) could be good for actual levellers, seeing as chests are largely ignored.