Slaying a Sacred Cow: No Character Advancement?

One of the great innovations of D&D is the level system, and especially the way the game advances in nice, big steps. This is a huge boon to new players, in particular, because it provides an immediate and obvious motivation for playing - you adventure to level up.

Of course, it's all a bit circular, since the big advantage of levelling up is that you can then go on tougher adventures in order to level up again, in order to go on tougher adventures, in order...

(The same is true of treasure, as well - you get magic items to make your character better so you can face tougher challenges to get better magic items.)

However, in a great many of the stories the game is emulating, characters don't really advance in anything like this manner. Yes, Luke Skywalker goes through the Hero's Journey and is vastly more powerful at the end of RotJ than at the start of SW (none of this "A New Hope" nonsense for me!). But the same isn't true of Han, Leia, Chewie, Wedge, or the others. Likewise, in "The Matrix", Neo gets advanced training to go from newbie to The One, but Morpheus and Trinity don't. And there are plenty of other examples.

So I'm wondering if many campaigns shouldn't just ditch character advancement entirely. Start the characters at 5th level (or whatever), and leave them there for the duration. (Even better in non-level-based systems, of course.) You'd probably need some sort of mechanism for tweaking the character over time, to allow for changes in focus, retraining, and the like, but these could simply be a matter of rearranging skills rather than adding them (because there are only so many hours in the day, and unused skills become rusty - spending hours training with weights will increase Strength, but it means you're not spending hours practicing Spanish and so that skill will fade).

I certainly wouldn't recommend this for every campaign, and I probably wouldn't even recommend a game omit character advancement entirely. But for some campaigns and some systems, it may be just the thing - strip out one more unneeded complication.