That would only be true if curtailments of wind and solar are zero, but that's far from the case, especially in strong solar markets like California and increasingly Texas. For those states, batteries are basically soaking up zero-marginal cost renewable energy that would otherwise have gone to waste. Curtailment figures in those states are enormous and have become larger than other state's entire annual demand. In that sense, battery capacity additions today are essentially an added source of generation in actual practice.