Whites are multiple orders of magnitude more competent than blacks and maybe an order of magnitude more competent than Hispanics/Asians, and even as tiny minorities we end up projecting a lot of power by dint of everybody being reliant on us. See South Africa as an example. Even with the farm murders and the systematic effort to rob Whites of their farmland, they can't really follow through too much because it would decimate their population from famine and become Zimbabwe 2.0.
Basically I think we'll persist even as a tiny minority because rival races can't get their shit together.