These days I bake most of my own bread so yeah, I know exactly what’s in it. Most of the time it’s whole wheat flour (real 100% whole wheat) mixed 50/50 with bread flour and just a bit of salt, oil, and a bit of sugar. Specifically 3 tablespoons across two loaves which, given my average slice size, works out to 1 gram of sugar per slice or 4 calories. As I’m not diabetic at this point in time I don’t worry about that although if someone asked I could leave that out entirely. Sometimes I add egg or milk or something else, and sometimes I use rye to make rye bread or add some oats or make a multi-grain…
(Contrast the 1 gram per slice in my bread to Hawaiian Sweet which is 7 grams per slice - it’s quite the difference)
I don’t recoil from commercially made white bread as if were poison but it’s not my daily fare. If it’s part of a decadent meal (like Thanksgiving) sure, why not? But it’s an occasional thing, not something eaten daily.
I don’t know when I learned white bread was less nutritionally sound than wheat - my family had wheat bread on the table when I was a child, although I recall some white as well. Certainly, by the time I was an adult and moving out on my own I knew that as a general rule wheat was better and that’s what I’ve been eating pretty much my whole life unless I was in a situation where white was the only choice.
It depends on the white bread.
If I make a loaf of white bread in my own kitchen using white bread flour (higher protein content), milk, and eggs with maybe a sprinkling of toasted sesame seeds on top with minimal or no added sugar then yes, there’s nutrition in that loaf. As opposed to a commercial loaf with stripped-down flour and lots of HFCS no, it’s not as nutritious. The OP wasn’t talking about good French bread from a boulangerie, they were talking about Wonder Bread which is a very different product.
In the very old days, as noted, white bread was a status food reserved for the wealthy and aristocracy. Such people weren’t eating just bread, their diets tended to be meat-heavy, which would supply B-vitamins lacking in their bread and thus would not suffer from pellagra or similar diseases. It was only when the poor were able to make white bread their daily bread, people who did not have a meat-heavy diet and during the early industrial age often had a pretty terrible diet, that such diseases started to show up in wheat-bread cultures.
In the pre-contact Americas there was no wheat, the grain culture was corn-based, but pellagra was avoided by either eating a substantial amount of meat and fish or, for the empire type cultures in Central and South America, by nixtamalization. ( Nixtamalization was also used in North America, but most Native/First Nations groups had a substantial animal flesh component to their diet. Groups like the Hopi, though definitely depended on the process for their maize.).
The big pellagra problem in the US happened in the Southern poor, people where corn was the dominant grain, nixtamalization was not a practice, and diets were poor in other nutritious foods. The mandate to fortify white bread helped alleviate these problems although really the best solution was a more varied diet with nutritious foods.