I don't understand why the US lacks some of these small but very helpful visual cues.

It's like the dollar bills all being green (and the same size?). If you have limited vision it's really hard to see the difference between the bills. I think every other currency I know uses different colours (and sizes) for each bill to make them easier to distinguish.

Same with street signs. Why use text like "speed limit" or "one way" when you can use symbols and colours for this? For people who can't read (English) it's so unnecessarily confusing.

And a last example I noticed again recently... Why is the nutritional information text on American products so confusing? It only says the amount of sugar, fat, carbs etc per serving. But a serving is such an arbitrary amount sometimes, I basically always want to know the percentage too so I can much more easily compare products. Like this.

I'm sure there's some things that are designed better in the US, but I remember these things from when I went to visit years ago and being quite surprised.

Yeah. Instead of having buttons for different grades, they just have different pumps. Also looking back at it, one is probably diesel, and one (the green one likely) is eco fuel / ethanol