the good thing about audio equipment that it doesn't take a lot of energy to make sound (in theory).
the problem is it's still quite inefficient, drivers only convert 30% of the electric power to sound power, 1 watt of electric power should be 120db at one meter ideally, which is definitely far far below speakers nowadays. speaker have sensitivities of 90db per watt per meter, significantly lower than 120db per watt, and that is the speaker loss, the rest is wasted in amplifier heat, amps struggle from their own inefficiency such as heat and component resistance, but they also struggle to phase mismatch and driver impedance mismatch with different frequencies, which is the main reason for wasted power