There are many brands of yogurt with "fruit on the bottom" or otherwise unmixed that use plain sugar. Not every store-bought product is the worst possible version of a store-bought product. There's a huge variation.

>> Not every store-bought product is the worst possible version of a store-bought product.

I agree with that for the general case but my intuition is that if someone's selling you something ready-made and pre-packaged, that you can easily make yourself (yogurt with fruit mixed in), then that's because they want to charge you extra and force you into a choice -of ingredients- you possibly wouldn't make.

For example, the yogurts with fruit I've had in the UK were just not very good yogurts, and the fruit were just not very good fruit. The yogurts were the thin and tasteless stuff that seems to be typical of anywhere outside the Balkans (I'm Greek) and the fruit were basically preserve, with added sugar. Why do you need added sugar with fruit? Because the fruit is under-ripe and probably too sour to eat in the first place.

You have to think of the economics a bit. Yogurt is cheap to make and most people won't pay a premium for it. Also it's sour and many people (again, outside the Balkans) don't like that. So companies will add sweeteners and sweet admixtures, like jam, honey or fruit to make it more palatable. And of course to make that financially viable they have to drop the quality of the ingredients. And that's where the additives come in: they improve packaging, transport and distribution, even as they degrade taste and nutrition.