You don't need 3000W, 1kW is plenty. I have a Yuba Mundo (one of the biggest long-tail cargo bikes) and my Bafang motor tops out around 1kW and it's plenty even

You don't need 3000W, 1kW is plenty. I have a Yuba Mundo (one of the biggest long-tail cargo bikes) and my Bafang motor tops out around 1kW and it's plenty even for the biggest hills here in Bloomington (which is quite hilly).