Out of all punctuation marks, comma is the shortest pause. For some people, she’s meaningless, but she could provide distance for those who need to stop with temporary spaces to rest, stop for a moment, and start again.
Although she exists because there are two or more sentences that stood in line and with their ego chose to stand alone, she is independent and rigid. She is there to force one to succumb gently and gives the other opportunity to explain. In contrast to full stop, commas give choices to these sentences to continue their journey. Gives them option to continue even without certainty, without knowing when and where the finish line is.
Comma gives hope — unlike period, he could stop any sentence; anywhere, anytime. A chance to explain, unlike question mark that hangs with a thousand possible answers. Provides time, and by its uniqueness is able to unite two contradictory statements in the same sentence.
Commas may not be special and are often overlooked. Not like a commanding exclamation point, not like a fierce dot, not like a hanging question mark. But commas are good and gentle, provide clear boundaries and opportunity for the sake of explanations; letting those sentences run as they are.