Excellent points on the futility of stable assets. Bitcoin seems to have evolved into a solution to global inflationary policy, specifically as a 'store of value coin' and countless altcoins seem to be attempting to replicate btc's success as a SoV coin. Clearly there is a decent level of demand for these SoV coins as an alternative to state fiat money.
Interestingly, Libra's not pegging to the USD for its 'stability', but to a basket of assets which the USD makes up a %.
If the ultimate SoV coin is not Bitcoin, might it be a coin pegged to a basket of assets that have historical precedent as stores of value? Precious metals, reits, btc, etc