When the dollar was back by gold, hard money, the dollar was not a big problem.
The lack of hardness in the dollar is the real problem. If a Bitcoin national reserve is created, the dollar can again become hard and dam the source of endless wars and theft by inflation.
Bitcoin cannot make the dollar what it is not. Even if it could, there is no benefit in doing so. The world will inevitably migrate to the harder money. But there is an advantage to be gained by the US trading its gold for BTC. That would be a step in the migration.
Just use bitcoin at that point
