what is the point of decaff?

Clearly, the point, is for people who are negatively affected by caffeine to be able to enjoy the taste of coffee or tea.

Decaffeination leaches much of the flavour from tea or coffee, though, leaving it tasting washed out and watery. Decaff tea, to me, tastes papery and flat. Decaff coffee loses many of the higher and lower notes to the flavour, and ends up tasting somewhat bandwidth-limited. (That is, acids and sugars which, to me, taste high and low are reduced, leaving some general “coffee” flavours, but without much in the way of nuance.)

The temptation, with decaff coffee, is to brew it longer or with more grounds. This might help with the feeling of weakness or watery characteristics, but it also gives it an overextracted flavour, leaving it bitter and harsh.

To me, there is not much point. I don’t want to drink overextracted, watery coffee or papery tea, so if I don’t want caffeine, I tend not to drink either.

Is there something that US have and the UK should have/do it too?

I’m not entirely sure I understand the question. It’s pretty broad.

I think the US has things that make it what it is, some of them good, many poor; but a direct one-for-one swap would not—from my perspective—necessarily bring the benefits they might have in the US. There is, for example, a culture of respect for teachers in the US which I would have liked to have experienced here. Students, still, feel the need to listen to and obey teachers.

However, the things about the society which make this possible are myriad, confusing and far from straightforward. A general respect for authority does, seemingly, exist to a greater extent in the US. But the respect can also manifest as fear, as of police. I instinctively felt fearful around police officers in my home town, probably because I was stopped many times as a teenager for no offense. This has not happened since I moved to the UK, and the culture here seems to be one of the police (generally) respecting citizens.

This, however manifests itself in a state which imposes itself in different, less obvious ways, and a culture in education of active disrespect from students of teachers.

These are gross generalisations, but I think my most basic answer is that the differences are complex, and a simple move from one to the other couldn’t work.

Oh, except coffee… there is generally better coffee available in the US. Though, US influence has given some roasters here a good foundation for great beans too.