That's like saying a home made burger from top notch ingredients is made with close to identical processes as a McDonald's one. Except of course that they use worse ingredients and cut on all possible costs as long as it still tastes kind of burger-like.
Unless you disagree that they for example replace a lot of the barley with rice and corn - I don't really see how can you claim it's the same thing.
"Unless you disagree that they for example replace a lot of the barley with rice and corn"
The ingredient lists of the "cheap" beers were, in most cases, set in the 1800s, and remain unchanged. And they were set when rice was much more expensive in the US. And indeed even today rice is neck and neck with barley -- they aren't saving a penny using rice. Instead it was used specifically because it gave a lighter taste, because, again and amazingly, this is a preference of many drinkers. Many Japanese beers are heavy on the rice, and are considered "premium" products for it.
The notions of expensive versus cheap as a patron of a brand are often completely detached from reality.
Unless you disagree that they for example replace a lot of the barley with rice and corn - I don't really see how can you claim it's the same thing.