Alright, so I decided to do the math, just to see how many American gold medals were earned by whites:
America won 39 gold medals in total.
22 of these were won by individual white athletes: Valarie Allman, Jade Carey, Ryan Crouser, Caeleb Dressel (x3), Amber English, Robert Finke (x2), Vincent Hancock, Nevin Harrison, Lydia Jacoby, Chase Kalisz, Nelly Korda, Katie Ledecky (x2), Carissa Moore, Katie Nageotte, William Shaner, David Taylor, Jennifer Valente, Anastasija Zolotic.
3 were won by teams of all white athletes: men's 4x100m freestyle relay (4/4 white), men's 4x100m medley relay (4/4 white), women's beach volleyball (2/2 white).
4 were won by teams including white athletes: women's 3x3 basketball (2/4 white), women's basketball (3/12 white), women's volleyball (7/12 white), women's water polo (12/13 white).
So now we add up 22 + 3 + 2/4 + 3/12 + 7/12 + 12/13, and we get 27.26 medals out of 39, which is 69.89% of all USA gold medals. Non-Hispanic whites make up 60.07% of the USA population (according to the most recent data), so it looks like they overachieved as usual!