1st, I really like your post.
And yet, there must be a balance between what we had in 1ed and what we have now. I like the fact that now a healbot is no longer required but at the same time, healing overnight is way too fast (without the help of magic) and can easily lead to the 5mwd and unthinking tactics because "Hey! Who cares? We'll get healed overnight". We (I?) want to play heroic narrative, not a cartoonesque one.
I want to see heroes at my table, not reckless, unthinking whirlwinds. I want the heroes to beat the big bad guys but yet I want them to fear for their lives. We now have a variety of groups. In older edition a four man party was like: 1 fighter, 1 cleric, 1 rogue, 1 wizard. Sometimes the rogue was replaced by a fighter/wizard/thief or a fighter/thief. The fighter could be replaced either by a barbarian, cavalier, or ranger (in rarer instances we could see the odd ranger/cleric and if stats were there, a paladin). Never or almost, were the full cleric (sometimes a druid but even then....) and wizard (I think I saw only one illusionnist in 1ed era) replaced by something else.
Only a fifth or sixth character would bring a much needed diversity. This is where we could see various multiclass races appear like a gnome illusionist/thief, a monk, a druid or whatever else would fit the party and the players at that time.
Now we can have varied party for almost no risk of tpk, which is good. On the other hand, I feel that a riskless environment promotes bad thinking. I want to see players feel the need for magical healing. And if they don't have it, then I want to see them think twice before charging in that room full of goblins/kobolds/orcs or whatever.
Yeah, I agree, resource planning (and other sorts too) are traditional parts of the D&D skillset. I don't have a problem with that, and it CAN co-exist, to an extent, with heroic 'action adventure' type play. After all, at some level the tension of the game only comes to fruition when SOMETHING is at stake, often the PCs themselves.
I just don't think that the change from, lets say, 3e to 4e, erased this aspect of the game. Consider a 1st level 4e party. They have buckled up and found 'Kobold Hall' (a sample adventure in the DMG) and now they're headed in! They have something like 6 or 7 HS each on average, and somewhere in the range of 20 HP. There's a cleric, so they can unleash a couple HS during combat (plus 2nd Wind if you really want, pretty much a dwarf thing though).
They enter the first encounter area, there will be SOME sort of attrition here, possibly something significant if one of the PCs is foolish or really unlucky. They will have to decide if they want to burn up their daily powers (each PC has one) or not, but probably not, because there's a resource game there!
Now they go on to the next couple of encounters, pretty much the same sort of questions, little bit tougher encounters with a variety of tactical situations. Clever play (avoiding traps, boldly advancing in the ball ball room when you realize what the tactical situation is, etc.) should reward the party with preserving their resources.
Encounter 4 is a bit more of a dilemma, its a tough encounter with complex terrain. Do you burn your best stuff here? It is hard for the PCs to know if anything else comes after. There isn't really a 100% 'right' answer here, nor is there a right answer to pressing on from here. Does the party turn back? There's no 'ticking clock', but presumably it is worth maximizing their treasure take. Yet a dead PC won't get much...
This is a pretty stock dungeon crawl really. It works fine in 4e in terms of resource depletion feeding into risk vs possible rewards (will the rest of the kobold tribe slip away with all the treasure if you rest). I don't see how it works differently from its 1e counterpart really, except the 'long rest' you might take is GUARANTEED to be 8 hours, whereas in 1e it would depend on the amount of damage taken vs how many CLW your cleric has left, etc. It could be a 2-day wait there.
I'd note that in no case does the dungeon tell you how to deal with this. The final 'big bad' White Dragon baby encounter isn't really explained in terms of whether the dragon will take off if the PCs don't push all the way to that last encounter. OTOH if they do, it is a badass encounter, which can easily TPK a depleted party (or even once in a while one that is simply unlucky and unskilled).
Not sure that 4e is really 'off the ranch' in comparison to earlier E's... 5e would play pretty much the same as well.