This is an interesting thread for me, because I'll admit I spent a big chunk of my career working for some of the companies discussed here. I don't disagree that almost no baked product is as good as it was 25 years ago, but the reasons haven't really been mentioned.
In about 1980 it became obvious that the bakery business had two major problems. The first problem was that most big bakeries were old, antiquated, full of asbestos, and located in parts of town that were no longer ideal for serving the suburbs efficiently or attracting well qualified employees. The second problem was that the distribution system comprised of an army of bread trucks driven by union salesmen delivering bread and cake to every grocery store and restaurant on almost a daily basis was no longer viable.
The answer to the first problem seemed simple. The corporate owners built new modern bakeries in the suburbs. They would be highly automated and very efficient. By and large they were a disaster. The automation didn't work, the cost savings were an illusion, and the old Black guys who had spent 30 years watching the Twinkies come out of the oven and making sure they were just right said to Hell with this and retired or quit. The classic example of this is Drake Cakes. They built a modern plant outside Philadelphia and it damn near broke the company because their product suffered so much and the new help didn't know their ass from a hole in the ground. They massively reformulated their product, not because they were looking to cut ingredient costs, but because they were trying to get a formula that would work on their new machinery. Nabisco is having many of the same problems right now because they moved their US production to Mexico. They can't duplicate the quality of what they used to bake in the USA. A lot of the products have never recovered. A Twinkie used to be a thing of beauty. It was complete crap as far as ingredients and nutrition was concerned, it's always been that, but their old plant in Chicago turned out a product with a taste and texture that was amazing. I worked for a competitor, and we couldn't come close to matching what they were putting out. It drove my bosses absolutely insane.
The other problem is that the distribution changed. Instead of those bread trucks and route salesmen going to every store every day they went to drop shipping their. product to grocery warehouses. The modern "super bakeries" also allowed them to ship farther and farther from the bakery (Entenmann's big push into the South mentioned earlier in this thread is a good example). To revisit the Twinkie, there was a time when the Twinkie you bought at a convenience store. in Chicago was probably delivered that morning, had left the bakery at 6AM, and probably came out of the oven at midnight. You were getting a product within hours. Freshness was almost guaranteed.
Now they were shipping it up to 600 miles to a grocery distribution facility where it would sit until it got loaded onto the truck to the individual grocery store, where it would sit in the backroom until some bored teenager pushed it out and put it on the bread rack. That baked good could be 3 or 4 days old before it ever even hit the shelf. When I was in the business the fresh bread we delivered on Monday would be pulled as stale on Thursday. Now you're lucky if it even hits the shelf by then.
To be fair, these changes were largely dictated by the grocers, not the bakers, but to deal with the new distribution system they needed to reformulate their products to increase its shelf life. All sorts of weird stuff has been added to keep the products moist, prevent mold, and generally extend the shelf life, none of it really having anything to do with taste or quality.
I've been out of the business for decades, so I'm on the outside looking in, but everything I see makes me glad I left when I did.
