[wtallis]

The extent to which a device relies on the battery as a capacitor even when plugged in depends on both the peak current draw of the device, and the size of the charger.

Smaller devices like phones tend to be paired with downright tiny chargers, but modern smartphone SoCs can draw a lot of power in short bursts (cf. all the controversy about Apple trying to prevent brown-outs when operating the phone with a worn-out battery). Apple's laptops are usually paired with power bricks that roughly match the maximum sustained power draw of the laptop. Windows gaming laptops tend to ship with power bricks that are 2-3x larger than any Apple power brick.