Why add sugar to a home made maranara sauce? Is it a chemical reaction to another ingredieant or is it simply for people who enjoy a sweeter sauce?

I have found that adding a little sugar to my sauce makes it a lot more red and adds a subtle sweeatness, that unless they are told what it is can't place why it is so good.

Adding sugar brings out the flavour of the tomatoes.

It cuts the acidity of the tomatoes a bit