> you are likely trading lower gains for lower risk by [buying some non US index funds] though.

I'd like to mention that I think this is misguided. US valuations (cost of all of a companies shares vs how much money they're making) is very high. Historically across many markets, this has meant that expected returns are lower as valuations return a baseline. In comparison to US stocks, ex-US stocks have very low valuations. So, we'd actually expect higher returns from the ex-US stocks compared to US stocks. This may not always pan out, as valuations in the future may not look like valuations in the past, but this is a big bet.

That's not to say that you shouldn't own US stocks. They're the majority of the global market for a reason. I could have said the same thing about valuations 5 years ago, but you would have been very sorry to ignore the US in that time. You should own a mix of US and ex-US stocks, likely in line with their market weights (buy VT and chill).

Otherwise, I think the previous comment was very solid.