I don't think so, you can do this well in D&D, and you can do it badly in narration-focused RPGs with mechanics allowing for various degrees of success. It's more about DM ability to let the party "fail forward" than about any particular system.
Yes it's easy to fall into the traditional boring "here's 5 orcs, now fight to death" trap, but it's more about the D&D culture than about the system itself.
D&D wasn't my first system (it wasn't popular in Poland - we mostly played WFRP) and I certainly did fall into that trap a lot early on.
In my experience DND has a very thin edge where the good experience exists. Outside of that its quite variable.
I cant comment on Warhams but other RPG's I have played dont really care about encounter difficulty. And I am not even talking about narrative only stuff. But even savage worlds I can go and find 10 wild cards or 20 wild cards or come up with almost any Ace, and its just a matter of player approach as to whether the encounter is difficult or simply deadly. To really create a TPK situation you would need to design enemies specifically to do that.