Oreos were made with dairy and lard originally.
Idk what you mean by "double cream" because there's no cream in Oreos lol
So many ingredients are switched around to make the product last longer in transportation and in the store. The thing though, is that food shouldn't be lasting months long in the first place. The longer something lasts without going bad, the less it should be considered food.
There are methods like canning or freezing that can make things last longer without adding a bunch of non-food preservatives.
Fresh baking is always going to be better. Most mass produced food in the US is not real food.
Fake milk
Fake butter
Fake meat
Fake whipped cream
Fake egg
Fake vanilla
I've met people who think Cool Whip is the most delicious thing. Many Americans don't know what actual whipped cream tastes like or even what real ice cream tastes like.