GDP = C + I + G + Xn = W + I + R + P

(To grossly simplify the single-nation macroeconomic picture, at least)

C = consumption I = investment (the first one) G = government Xn = net exports

W = wages paid to labor I = interest on capital R = rent on resources and real property P = profit to entrepreneurs

consumption ~= wages, so if wages go to zero, the economy massively shrinks unless government steps in with something like taxation to fund UBI, sovereign wealth fund distributions, or direct universal ownership.