Can someone please explain to me what the point of having an eq pedal is?
Usually, to counteract the problem of somebody having bought the wrong and/or cheap guitar, wrong and/or cheap amp, wrong and/or cheap distortion, or simply not having properly set the EQ on their amp/distortion pedal in the first place.

It adjusts the sound at different frequencies, allowing you to have more control over the tiniest of details of the tone you are producing.

Because of the way sound interacts with different environments, and the relative inefficiencies involved in trying to hear a sound when standing close to the amp producing it (like say, within 30 feet), it takes a long time for a guitarist to have developed enough ear training to where an EQ pedal actually becomes an intelligent buy.
it boosts or subtracts more points of bass and treble than an average amp does