In the view of a global economy, would it make sense to create a stablecoin, which is algorithmically stabilized on a price which is a weighted average of all the major currencies?
This is basically exactly what Facebook is planning to do with its crypto-currency, whose value is based on a basket of currencies and for which the company has received enormous headwind from governments and financial companies around the globe. If Facebook has had enormous difficulties in implementing such an idea so far, then I don't think we need to discuss whether anyone else could (legally) implement it.