Electric guitars use steel strings rather than nylon strings because the steel strings produce a louder sound when amplified. Although they lack the traditional, warm tone, or "twang" of nylon strings, Steel strings are preferred by musicians who wish to play heavy rock and metal music, which heavily relies on electrical amplification and distortion.
To achieve a brighter tone
Steel strings produce a brighter sound, with more sustain, and a more consistent tone. This is because steel has a higher density and stiffness than nylon, which means that steel strings vibrate less when they are plucked. The result is a tone that is clear, focused, and cutting, which is ideal for genres like rock, blues, and country music.
Steel strings are more durable than nylon strings
Because they are less prone to stretching or breaking, steel strings are more reliable for live performances and can last longer before they need to be replaced. This makes them a good choice for musicians who play regularly or who tour frequently.