You need to add sugar to contrast tomato acidity, it has nothing to do with sugar addiction.
And it has been like this since forever, not only from the '70s.
Source: even my grandmother added a pinch of sugar when cooking pasta sauce.
In terms of taking the edge off of tomato sauce, shredded carrots works pretty well. I don't use sugar in any of my cooking, and no one has noticed.
If you think that's not true, simply take a sugar-low bread (check the food label, don't just go for organic/whole-grain, those usually have more sugar) and taste it for a while in your mouth. You'll notice it starts to become sweeter in your mouth.
As long as you stick to proper bread without the crazy added sugar, and preferably whole grain (actual whole grain, not just marketing "whole grain"), it's not an issue. Unless you try to subsist on literally only bread, of course.