We need global trade as we want to produce the best and consume the best and do it (multi-) planet scale.

Even if you argue for one type of currency, you argue for BTC. You still need to get a reserve which every one accepts, in exchange of your own currency (work).

The only option is BTC, as all transactions are immutable (final) and already funded by a one source. Otherwise you have no reserve and if there is a reserve, it is not yours!