> The euro is in a much better position to be adopted as an alternative, but its share of global reserves has been flat at around 20% for years.
The Euro is only 25 years old: it would be pure folly to make the "reserve currency" something that recent.
Then... One country of the eurozone already partially defaulted on its public debt (Greece, in 2015). And France is running an insane deficit: so bad that there are now talks of the International Monetary Fund taking control of France's public finances. France had to raise the yield on its debt to its highest level since nearly 20 years. France cannot reach the "only 5% of GDP" in yearly public deficit, on top of an already insane public debt: it is snowballing and the only outcomes are going to be miserable for the people (and for the EUR).
An economist, before the EUR began circulating, explained by which mechanisms the EUR would lead to Spain, Greece and then France default on their public debts. That economist explained how the EUR would lead to "too many secondary houses in Spain" and "too many public servants in France". When Greece did default on its debt, that economist said: "I was only wrong on the order on which these countries would default".
One would be crazy to make a reserve currency a currency that's a mix up of countries that have different productivity and different fiscal laws.
The EUR is one of the worst currency ever conceived and it could turn out to also be one of the shortest lived currency.