I'm sorry, but no. That's a cool campaign set-up, but it's something that I absolutely would not want the game to mandate for me. If I want my PCs to grow to the point where they are Qui-Gon Jinn or Yoda, and then continue to advance, then the game shouldn't be working to stop me.
Agreed. Plus, it would be fairly easy to bolt that on top of a more traditional D&D system, as an option.
For such a campaign, you have a "destiny" resource that is renewable each session, adventure, week, year, whatever makes sense, and you might gain trace amounts from major quests. You can use this to do "fate" type things, perhaps. However it is set up, it is useful.
Through the first 10 levels or so, every level adds to your destiny points (your working total). After that, gaining a level gives you the usual benefits, but starts
costing destiny points, permanently. This escalates going up and escalates going down, so that it gets progressively more expensive in destiny to achieve the higher levels. Every character finally reaches a point where it takes an immense amount of questing to pay for the next level, and paying for it trades this next level of power for reduced effectiveness in active destiny points.
To vary the pace, change the "switchover" point, moving it up or down the levels and/or adjusting the points gained or lost. If you want something more like Star Wars, you start with an immense amount of destiny, but begin losing it almost immediately. If you want something more like high level BECMI/RC, then you start with none, gain it slowly, and don't start paying out until you near the Immortal range.