Just to push back on this slightly, I'm sure I've watched Youtube videos with someone who bake cakes for a living who said they used boxed mixture for most of their baking.

As others have said elsewhere, some of the ingredients involved are not easily available/cost-efficient for the home baker. This means it's more than possible that you will get an objectively better cake from a mix, e.g. from blind tasting.

This does depend on the type of cake you're baking and your expectations of 'better' though.

> someone who bake cakes for a living who said they used boxed mixture for most of their baking.

Would love to see such a video. I could imagine using certain box mixes for certain specific purposes, but for most of their baking? I cannot imagine this being claimed by even a casual cook/baker.

> some of the ingredients involved are not easily available/cost-efficient for the home baker

Sure, but some of these are also only necessary because the box has to have a very long shelf life. If you buy your staple ingredients every month or two, you don't need stabilizers and such.

Do you have an example of these unreachable ingredients? The main ones - dextrose, whey, emulsifiers - can be found at any supermarket as "bread improver" or "dough conditioner" mix.

Maybe expectations for cake in the USA are different from the rest of the world, like it is for sliced bread (soft as a pillow). I seriously doubt bakeries in most of europe use cake mixes, or at least nothing with a similar laundry list of chemicals.

So someone who is used to industrialized cake baking prefers industrialized cake recipes? What exactly do you think this means about the quality of cake you can bake from scratch at home? Do you really need a cake expert to tell you what cake is good??

Blind testing is missing the point - you're not trying to emulate some perfect standard. The little imperfections and variances in the result are the value.