It's not all that tasty. After visiting Europe I always find American foods to be grossly sweet. It's a race to the bottom that you only notice if you get out of the cycle for a bit.
Because it's actually better or because of confirmation bias or because as a "visitor" your diet is not representative of what people who live their eat on a normal day/week?
I believe like for like on products, some food's in the US are of a lower quality due to food standard laws being poorer. Chocolate for example must include 10% cacao in the US and 20% in Europe, hence Europe's will taste different and more chocolatey as it simply has more of the ingredient that gives chocolate it's flavour. Chocolate of course isn't the only product that has different regulations.
Un-processed poultry (like breasts or something, not nuggets) was the big one I was thinking of. European stuff is higher quality in that there's less chemicals involved and it's cleaner but those are mostly public health issues (no salmonella outbreaks), not nutritional issues. If Europeans aren't actually eating in serious volume the classes of products where the differences are then it doesn't matter much if at all. And then there's all the products where it's a distinction without a difference, like eggs.
As a single point of anecdote - as a European visiting America, I also found American candy just insanely sweet. Like, way more than what I'm used to, and it definitely didn't make me go "wow this is tasty". I guess you're used to what you know, but there is something to it.
I do agree that our sweet here in NA is sweeter. From a taste perspective however, it's a lot about whatever you are used to, like you say.
After more than a year of Keto and not having had any bread, I ate some wheat bread again for the first time. Nothing sweet on top. Just bread (with butter on top). It tasted sweet! And it wasn't even your typical North American floppy toast white bread but just regular, proper wheat bread like you might eat in France in your neighborhood corner bakery (here they usually call it "artisan bread" now).
That sweetness went away really quickly after eating bread more regularly again but it surprised me nonetheless and makes your point on getting used to things.
Another NA example is cup cakes. There are cup cakes and then there are US cup cakes. I really don't like cup cakes at all. I avoid them. It's a tiny bit of cream with a ton of sugar. Just disgusting. They do the same with actual cakes. You can't buy a proper cake with cream based frosting and some tactful addition of sugar. It's a tiny amount of cream with a load of sugar on a tasteless body of (in many cases overly dry) sponge cake.
