I was explaining this to my daughter in quite simplified terms the other day- we evolved to taste sugar and enjoy it because finding a sweet edible plant meant we had a source of energy to help us hunt that day. Pretty useful if you’re a hunter-gatherer.
So we seek out sugar. Now we can get it whenever we want it, in much more massive quantities than we are supposed to be processing. Most of us are addicted. I’m not an exception.
Do they contain more sugars by default perhaps?
Yes, but San Marzano tomatoes that are sweeter are still only 3g of sugar per 100g, and 2g of net carbs per 100g.
And if you make a mirepoix for your sauce, the sugars in onions and carrots are higher.
So for people that are afraid of sugar, a sauce made with tomatoes, carrots, onions and celery isn’t as scary as adding sugar.
And the acidity isn’t considered as well. From experience, they are less acidic as well, so you don’t need to add sugar to mask that.