Without disputing any of your other points, you’re just dead wrong about this one. Look up dispatchability. Turbine driven power can go from zero to full multimegawatt power and back in very little time since we control the fuel. You cannot turn up the wind, nor the sun at night.
Nuclear power can be shut down very quickly, even more quickly in gen4. You have good points and you need not disrupt them by claiming renewables are good for demand response.
To clarify, I mean steam turbines but the same is true of wind turbines. Like you said, easy to disconnect them from generation. The difference is maximum power is limited by fuel rather than nature.