As time goes on, fewer people are alive that predate the EU and more people will perceive it as a lasting institution.
Additionally, we've now seen the EU survive the departure of a major economic power (the UK). More people are certainly willing to believe in the stability of the EU now.
Another major currency is the Yuan, and some countries may be as willing to trade in Yuan to improve relations with China, so perhaps we won't see one single reserve currency but two spheres of influence with most countries maintaining reserves of multiple currencies.
Additionally, we've now seen the EU survive the departure of a major economic power (the UK). More people are certainly willing to believe in the stability of the EU now.
Another major currency is the Yuan, and some countries may be as willing to trade in Yuan to improve relations with China, so perhaps we won't see one single reserve currency but two spheres of influence with most countries maintaining reserves of multiple currencies.