Genuine question for Americans, as we don’t tend to use them as much in the UK:
Why do you use shades or blinds, instead of curtains?
Also good lord these are expensive
1. I use smart blinds because they are very useful. They can dramatically reduce your heating/cooling costs if properly automated, as well as just making the home more pleasant by making it more magical -- it just "does things" correctly to maintain homeostasis regardless of rain or sun, hot or cold.
I think Americans, generically, use blinds along with curtains as just one more option. There are dozens of styles of blinds (most of which suck!) for people who want any particular sort of look; there's only one style of curtain.
So people who care about looks more than functionality gravitate towards blinds. People like me who care about functionality also gravitate towards them, but to the very specific subset of blinds that are not garbage.
Smart blinds predominate because it's not too difficult build a roller design (like these, or the Ikea smart blinds) with a small motor and battery. You can also try to motorize tilt blinds, but that's generally been less successful - there are all those strings and inevitably after many years something goes wrong, the tension becomes uneven, etc.
I would not say this is yet a solved space. If you live in the south, so sun is your primary concern, smart roller blinds do exactly what you want. If you live in the north and temperature is more of a concern, you may want a blind that consists more of air cells, to provide some additional insulation, and I haven't yet seen a smart version of those.
2. I don't want to be a dick, but these are just not very expensive by American standards. They are more expensive than the old Ikea smart blinds, but not insanely more so, and they are nicer looking and probably more robust. (I live without kids, but I could imagine that kids occasionally yanking on the Ikea blinds could be an issue).
Let's not get political, but it's the difference in what counts as moderate income by national standards that's the discrepancy here. As to the reason for that discrepancy, well thats a subject for the political threads.