“all currencies in the world are based on very little underlying economic wealth”
Actually they are backed up by more economic wealth than the world has ever seen. In the US, $21 trillion or so. In the EU, about 14 trillion euros.
Gold reserves in the US are worth about $0.5 trillion. Returning to the gold standard woiuld result in a massive contraction of the economy because of the need to withdraw over 95% of the currency from circulation. Winston Churchill once said that the biggest mistake he ever made in his political career was returning the UK to the gold standard.