Is the gap between US and euro-zone equity market indices understandable?

Since mid-2017, the US equity market index has risen much more than its counterpart in the euro zone. But comparing equity market indices makes no sense: one must compare the return on equities, as the dividend yield is much higher in the euro zone than in the United States. We then see that the total return has been significantly higher in the United States, i.e. by 4.5 percentage points per year over the period 2014-2019. Next, returns on equities must be compared with risk-free interest rates, i.e. ex post equity risk premia. This shows that the US market outperformed the European market by 2.6 percentage points per year over the period 2014-2019: US equities have still outperformed significantly.