As a recording engineer, everything about this comment is factually wrong.

EQ absolutely can improve the sound. That's why we use it in our mixes, and if your listening gear has odd tonality, then of course adjusting that can improve the sound. It's not debatable.

And we use studio monitors EQ'd (gasp) to flat at the placement of our heads when mixing and mastering, then listen to it on various common devices to ensure there's nothing horribly wrong on any of them.

Please don't spread misinformation.