I don't think either of those are true - at least not an any bakery I've ever been to.
Cakes are a very specific type of baked good, made with a batter not a dough, which do not use yeast for leavening. Cakes also do not rely on gluten, and in fact limit it's formation by utilizing low protein flour.
Also, bread dough will never 'pour' unless you've gone horribly wrong.
For batter vs. dough: yes, they are not the same, but adding any fat to dough inhibits glutten (e.g., https://cooking.stackexchange.com/questions/36267/how-does-f...), which is why sandwich bread is soft and spongy. It may not pour, but neither does muffin batter or brownies, for example. My point is there is a whole spectrum for gluten formation.
Compare the cake recipe https://www.kingarthurbaking.com/recipes/classic-birthday-ca... to the bread recipe above. The main difference is that butter is added along with eggs, and the leavening is different. Artisan bread only has the 4 ingredients, sandwich bread adds sugar, milk, and oil, and cake changes leavening and adds eggs/butter. As you go up the spectrum, you are intentionally avoiding strong gluten development, resulting in smaller holes and softer texture. See challah bread for another data point of bread with eggs+oil https://www.kingarthurbaking.com/recipes/classic-challah-rec.... You can also make the gluten weak by using something like 100% rye, which has to be baked in the same tin (though that would have a harder crust).
The cake recipe has a 2:3 ratio of flour to sugar, while the bread recipe has a 14:1 ratio. It also has a 2:1 ratio of flour to fat, with the bread being 6:1. The cake also has a much higher hydration ratio, more milk, eggs, and a completely different mixing process.
Really not "essentially" the same thing at all.
Do you really mean mixing, or rather kneading?
Kneading bread is very hard work; occasionally I do it for a single loaf, but it really doesn't scale above 1 or 2 loaves. Even artisinal bakeries have machines for it.
After a moment, they look at me and ask where we can get some.
I tend to bake two loaves (always with tangzhong if the particular recipe can tolerate it), wrap both, immediately freeze one, and the other one lasts somewhere short of a week.
No preservatives necessary. You just need a freezer and a toaster.
Which storing bread that has a crust worth preserving, I tend to make sure it gets a little air (covering it with linen cloths, for example), and accept the small amount of drying out that comes with this form of storage.
The bread parent linked (and most German breads for that matter) is a rye bread!
Ingredients: Artisan bread is usually just flour, water, salt, yeast (sourdough is just flour and water, too). Sandwich bread can include milk or other fats to make it softer and is more of a “cake”. In industrial settings, there are a lot of preservatives included in the sandwich bread.
Mixing: Artisan bread is mixed by hand. Sandwich bread is mixed in a mixer. The former thus has less worked gluten.
Shaping: Artisan bread is made into a ball (similar to “spinning” pizza dough). Sandwich bread is poured into a tin and requires no shaping.
Bake: Artisan bread is baked at high heat, around 500F, in steam. Sandwich bread is baked in a specific tin at lower heat, like a cake.
As you can see, the sandwich bread is easily scalable and, being essentially a cake, is preferred by many. A loaf of sandwich bread is around $1-$2 where an artisan bread is like 4x more.
Also, there are flours, like rye, which have to be made with sandwich-type methods. These flours don’t have enough gluten to hold shape on their own.