However I think power advancement can change the story so much that tadah people do not play high level D&D nearly so much.
Yes, in D&D, play starts as one thing, and it changes as power rises. I don't deny that. But let us be careful...
Folks who play D&D most certainly can say, "I want to play a character that is the Best Swordsman." They just have to
start at high level. Then, across play the game would not change so much. Ergo, "the game changes too much" isn't really the barrier.
The thing we are missing is that there's likely a stark difference between the concept in your head of the experience of "the best swordsman" and the experience high level D&D supplies.
D&D combat is, to this day, squad level tactical wargaming. In D&D, you have a whole bunch of combat mechanics bits, and when it is over, you find the resulting narrative is that the character is the Best Swordsman, because, empirically, it has been proven such.
But the Best Swordsman is.. Inigo Montoya. He doesn't win because he has these feats, those class abilities, this other subclass, and a huge bag of hit points. He wins because he is the Best Swordsman. The only way to beat him is to use something other than Swordsmanship.
Correct me if I am wrong - but in a game where you want to step in and declare that your character is the Best Swordsman, you ought to
start with that declaration, and have things cascade from that fact, rather than have a bunch of other stats that
add up to that fact.
Here's the thing that gets lost in this discussion. D&D has something that, say, Fate, or Cortex+ does not - extensive headroom.
I think, if you set down to it, games with people who step into the Best Swordsman role directly last
no longer than a typical D&D campaign. Probably less, in fact, because if you start at the top... where you going to go? How much story can you tell before you start getting repetitive?
D&D's power growth, and the change of game that it includes, is a
feature, not a bug. After a while of play in games that don't have power growth, eventually it gets old, the character has been fully explored in both the tactical and dramatic senses, and typically folks wrap it up, and play something else.
In D&D, after a while of play, you have a choice - wrap it up at the power level you prefer and start something else,
or you can keep playing, and the game will change it up for you, without having to wrap up and create a new continuity. A D&D character kind of refreshes in each tier of play, which cannot be said for the Greatest Swordsman, who is pretty much stuck where they started forever.