Just because someone can't explain the reason in actual scientific terms, does not mean that the improvement in sound quality doesn't exist.
Audiophiles use their ears to evaluate whether a given component improves or degrades the sound quality, while polkalovers rely on measurements to tell them what they like.
Of course, you knew this when you asked the question.
Or maybe you actually do believe that the hundreds of thousands of audiophiles that buy expensive streamers or dacs are all fooling themselves and only you know the truth.