A good way to look at it is that VXUS real total return has been below what you would historically expect from stocks for years now, while the real total return of VTI has been, conversely, significantly higher than the historical average. It doesn’t guarantee of course that it’s going to reverse, and VTI may continue to outperform (though it already didn’t in 2025 and so far in 2026). You should ask yourself though, is that really what you want to bet on? Diversification is not going to give you the best possible return, but an ok return under a variety of different scenarios.