Why do emerging markets ETFs trail US Total Market when their GDPs are largely higher?

So as a young person I have been investing about 80% in US equities and 20% in international/emerging markets, since I'm betting on global diversification and growth in those markets. I also look at GDP growth in places like China, India, etc, and see that they are largely outpacing the US. However, that is not translating to returns that outpace the US

For example looking at FSKAX (US Total Markets)

17.50% 1 year, 11.54% 3 year, 16.05% 5 year, 12.30% 10 year annualized returns

Then looking at FPADX (Emerging Equities - about 65% composed of China/India/Taiwan)

9.98% 1 year, 0.30% 3 year, 3.89% 5 year, 3.23% 10 year annualized return

What am I not understanding? I realize that these are just baskets of individual holdings, but I would expect to see these emerging markets doing better than they are. Is this a matter of more money being pumped into the US so prices are rising faster even if GDP is going slower? Is GDP just flat out a wrong proxy to be thinking out potential market growth?

Appreciate any insight from those who know more

Thanks