Your problem with this hypothetical endgame is an appeal to fairness.
I understand why you'd want that, fairness is a strong human instinct, but I don't see where it has any bearing on the likelihood of this future occurring.
People don't enjoy having a high number in their accounting system, they enjoy being wealthy. If, say, African central banks start purchasing BTC, and India joins them, early adopters will cash out at whatever value makes them feel like they got their money's worth. Some people will only trade for real property. Some are in a position to hodl until they can buy a whole cruise ship or whatever.
Or they could lose it all when BTC crashes to the natural value of any completely hypothetical asset, which is zero. This still seems more likely to me than central banks taking up a position in BTC, but sadly, I lack the ability to predict the future.
Is it really that different from buying the first iPod, and thinking to yourself, "y'know this is a brand new Apple, I'm putting a few thousand bucks into their stock"?