Why high ISO is not a bad thing?

In the world of photography, few terms stir up as much confusion and fear as "high ISO." Whether you're an aspiring photographer or a seasoned pro, chances are you've encountered the debate about whether increasing ISO leads to a decrease in image quality. The common belief is that higher ISO settings result in grainy or noisy photos, but this perspective doesn’t paint the whole picture. High ISO doesn’t mean your photo can’t be published in a magazine or printed for an exhibition. So why are we scared of it so much?