The EQs should be used;
1) to balance the way the sound is heard. No two rooms will sound the same because the shape and material of the room, the number of people in the room, the humidity and any other sounds that conflict with the tune are always different.
2) to emphasize a range of sounds by either enhancing (or reducing) them, like a singer in a choir or to reduce played sounds… mainly as a technique. ‘Kills’ (a switched removal of that range of sounds) do this very well.
3) to turn up (or down) sections of the song so that transitions don’t stand out such as having instruments being much louder than the previous track or (as stated above) to replace the beat of one song with another (which is a great transition technique).
4) to reduce damage to equipment from distortion (hopefully to zero) while music is still being played at high volume.