For one thing, the famous epic NPC's in FR are not 40th level, not even near it. A few are in the low 20's. I think Elminster is around 26. A lot aren't even epic level. PC's in their mid to upper teens, especially using lots of 3.5 splatbooks, could easily run with them. Exactly why do the PC's have to be the highest level characters on the planet to accomplish anything?
It was likely hyperbolic to rate Elminster as being 43rd level. I think he's in his thirties, and Manshoon and/or Fzoul might break into that range. What matter? The specific number isn't important to convey, just that they're not just epic, they're epic enough to dward other epic characters. Drizz't and Jarlaxle are refreshingly unepic, weighing in around 16-17th level IIRC. I guess if you obsess over killing orcs--even lots of them--it's bound to impede your progress.
But that whole line of thinking goes back to the notion that the NPC's have to show up to actually overshadow. Knowing that they are the current and active forces in shaping the realms means is enough to make some folks feel like they're just a squirrel trying to get a nut.
Good luck finding a campaign setting where your 1st level PC's are the baddest things in the whole world. All established campaign settings have a number of high level NPC's. The FR ones are just more well known because of the novels. Do the PC's have to be the most powerful beings on the continent to not be so "overshadowed" that they can actually do any adventuring? Do the PC's say, "Well I was going to go save that village, but since I'm first level and there's a 3rd level wizard that lives in that tower over there, I guess I'll just let him take care of it." Really, are the PC's going to be whiny crybabies because they aren't the baddest guys around, or do they suck it up and go do some adventuring?
I was kind of hoping you'd step up your game at this point in the discussion, but you are slow to absorb and quick to belittle. If people enjoy playing in FR, good for them. If they don't enjoy playing in FR, it's not their burden to not be a "whiny crybaby" and "suck it up". Find a setting that everybody's happy with.
Eberron is actually set up with the specific intention of avoiding FR's pitfaulls, placing the PC's on the path to become principal heroes of the world. The few high-level NPC's are generally locked-out of adventuring in some fashion. You don't have someone like the Symbul single-handedly holding off invasions, turning into a ball of energy and shattering entire armies. Dark Sun and Ravenloft both have plenty of territory for heroes to carve out; the people of thsoe worlds need all the help they can get. Greyhawk's arch-characters have basically done what 4e suggests that epic characters do when they hit level 30: gracefully fade into the background.
Note that last bit, because it's key. The FR epics were just incredibly active forces. That's the stark contrast between the pre-4e FR epics and those of other worlds, and Ed Stark has often gone on the record saying his preference to have Elminster be a colorful background character was thwarted by those who wanted the character to keep selling novels. He kept getting pressed into service as a quarterback when Ed thought of him more as a mascot.
To sum up this whole discussion, if a player said, "Why should we try to handle this problem? Why doesn't Elminster do it?" My response would be, "Elminster isn't here, but you are."
Right, exactly in line with my previous comments: the trick to making this work is to refrain from looking at the big picture and just focus on the task at hand. It is essentially a rejection of the question instead of an answer. Suffice to say, we are not faced with dismissing this question now because 4e's designers saw the problem with Elminster, the Seven Sisters, and the other overshadowing epics running around willy-nilly and addressed it.
Felon, I guess it also comes down to what your definition of "cool" is, doesn't it?
Indeed. To each their own.