Ok, it's interesting that the law in Ireland requires a 2% or less baker's weight of sugar. And I do enjoy a good sourdough, which isn't made with any sugar, or just a pinch.
But my favourite sandwich bread is Japanese milk bread, it's soft, lovely crumb, and it browns beautifully in the pan.
It's got a lot of sugar in it, that's the secret. A random recipe I found says 18% baker's weight, which seems accurate.
Are we pretending that polysaccharides are the staff of life, but when you get down to disaccharides they become the Devil? The glycemic index of white flour is dire, I doubt adding sugar is going to move the needle.
Sugar in dough makes it soft, with a giving crumb, and a crust which can be brown without becoming hard.
Exactly what you want in a sandwich filled with toppings, so that they don't shoot out the back when you bite into it.
Clutch your pearls all you want about 'Subway misrepresenting healthy food'! They publish the macros of their sandwiches. It's not nearly so healthy as eggs scrambled in butter, there's a ton of carbs and not nearly enough fat.
Unless you think it's the other way around that's healthy. It's your stomach, you get to pick.