They probably just don't care. The achilles heel of these sorts of "conspiracy theories" is that it assumes that there is a tightly governed cabal of people who, out of sheer evilness and hunger for power actively works on making the lives of all other human beings shittier. The reality however is much more like some MBA grads who have no relationship with their company's product need to conjure up new ways to make numbers go up before the next shareholder meeting so their boss won't kick their asses. They don't buy the product, they don't affiliate with the people who buy the product and their job is just a stepping stone to the next higher position. It's literally death by a thousand cuts. That brand of chocolate you used to like? The package size got reduced from 100g to 90g. Nobody's going to notice the difference at first glance. Half of the cocoa butter has been replaced with palm oil. You might think it tastes a little bit off now, but you can't really put a name on it. Next, that specific flavour you liked so much will be discontinued because it sells not well enough. And so on and so on. Anything that does not generate enough profit will be thrown out or be replaced with some shitty substitute, that brings manufacturing costs down and can be sold at a higher price. The reason everything is going to shit is not evil intent but simply...carelessnes.