Should I bail on international stocks in my 401k?

Hi, I have a company 401k, and I can't choose individual stocks, but there are lots of different funds I can choose between. When I set it up, I didn't have a ton of time to research all the funds but I included an international fund (MDIHX) to get exposure to non-us stocks.

However, I've learned more about stocks in general since then. And it seems like MDIHX is lower volatility and lower overall returns than a regular US fund (i.e. S&P500) , and that's looking back for as long as the fund has existed, almost 20 years.

Should I slowly lower my investment in it and move the money to US funds? I'm young and can afford to let my 401k ride out the highs and lows of the US market. Are there any other factors I should consider? Also, the fund has a high expense ratio, but it is waived for our 401k.

Thanks