The powerful NPC's in the Realms have responsibilties that keep them from always being around to solve every problem. Even if all they did was going around slaying Zhents and orc hordes, saving villages, etc. they couldn't do it all. They are still mortal and can't be in two places at once. The Realms is a huge place, and there is plenty of adventure for everyone. There are plenty of opportunities for PC's to be the heroes. Besides, the superpowers of the Realms realize that directly confronting each other could be disastrous for both sides. If you are a powerful wizard, do you risk your own life or have your underlings do things for you? There is even a sidebar in the 3.0 FRCS where Elmister uses this same type of arguement to explain why he just doesn't go and try to take out Fzoul or Szass Tam. I will say it once again, if NPC's are the focus of a FR campaign, it's because the DM wants it that way, not because the setting demands that it be that way
I ran a long-running FR campaign in 3.5, and the PC's only met one the "famous" FR NPC's, and they were too preoccupied with their own concerns to go and do the PC's job for them, which is exactly as it should be. It wasn't just hand-waving. It made perfect sense, and the PC's got to be heroes. I never felt the need to have Elminster just come and blow the enemies to bits or have Drizzt cut a path of destruction through the orc horde to save or show up the PC's. If you really take a look at the stats of the NPC's in the 3.0 FRCS, they are not that powerful compared to high level PC's. Yes, they are very high level, but really not that impressive when you look at their stats closely.
"For a 43rd-level wizard, Elminster is kind of meh."
OK, let's come to consensus that if the party is level 40+, they should be able to operate in the realms without worrying about being overshadowed. I am big enough of a man to concede that.
But for a lot of folks, D&D's sweet spot is 6th-10th level. How about those guys?
Shaz, your posts are fixating on the notion of FR NPC's appearing on the scene and upstaging the characters. That doesn't really get to the heart of what I or others are trying to convey when we talk about the presence of all these epic characters overshadowing a party of characters trying to carve out their own legend. As I replied to Hawkeye, it has at least as much to do with the knowledge that whatever "level-appropriate" thing your PC's are doing, the really cool stuff is being handled by someone else. Your explanation that the big boys are preoccupied and delegate their light work to underlings (i.e. the PC's) is not a source of consolation, but consternation.
Sure Elminister is too preoccupied to help me kill kobolds. He's got bigger things to be doing, like preventing a demon lord from invading the mortal plane. But the kobolds hassling a few thatch huts full of muck farmers? They're all mine. Now, let's say those kobolds could amass sufficient numbers that they might hope to pose a threat to an entire region, including a place like Silverymoon or Waterdeep or Cormyr, then my party is now handling a major threat which is substantially cooler than bailing out muck farmers. But then the scenario has expanded to the point where it begs the question as to how the rather numerous and powerful protectorates the aforementioned places already have can be too preoccupied to intervene in the razing of their cities by a bunch of uppity kobolds.
Now one day, if my party puts our nose to the grindstone and spends a few years playing, we'll be epic-level. But that won't be a turning point for the realms. It's not like, say, Dark Sun, where the world is crying out for some heroes to get that powerful. We've been beaten to that punch. The ground is well-tread. We're late to the party, and at 21st-level, we're still scrubs.
All of that is what folks mean when they say playing FR felt like playing a minor character in Star Wars. We don't need to be physically shoved out of the way by Luke Skywalker and Darth Vader banging lightsabers together to be made aware that we are supporting cast in their universe. It feels that way without ever having to cross paths with them. As far as I'm hearing, the solution is to not take the big-picture view of the realms. Focus on what's placed before you, and be content with the little slice you're aiming to carve out.