It's fascinating to live in the US and Canada (having previously lived in the UK) and read these threads. There really are a lot of misconceptions.
The US and Canada are HUGE. When you watch a property programme you may be seeing houses in a state like Florida (hot and humid), a state in the Midwest (hot summers, cold winters), a state like mine in the Rockies (dry as a bone), etc. So you can't say "there are no radiators" or "all the heating is air through a vent". Radiators are common in my dry climate state because the moisture from the hot water in them stops all our hardwood floors from dessicating and our skin from flaking off. If you tried using hot water heat in a damp place like Washington State, your house would fill with mould in a matter of days. Heating systems are different all over and are complementary to the climate of the area.
You're seeing 'dark wood everywhere' in kitchens most likely because the programmes are a few years old by the time they reach you over there. The trend now is for lighter cabinets. We are less keen on carpets because of germs etc and because our central heating is really efficient! Most people want some form of hardwood, and carpet is right now out of fashion.
I can't think of anyone I know who would prefer a wardrobe to a closet. Even friends in the UK! Wardrobes take up far too much space and are often ugly.
The PP who said her friend in the US just lets his dog out and it runs around the neighbourhood? Maybe that's in rural deep south, but cities and towns in the US tend to be much more strict on off-leash and loose dogs than in the UK and that dog would be taken to the pound very quickly in most areas. There are specific fenced dog parks for dogs to go off-leash in, usually the size of a small field.
We have one of those open plan homes that so many in the UK seem to hate. The difference is that because it's in the US, it's a big open plan - our main floor is 2000sqft+ and someone sitting one one side of it would have to shout for someone on the other side of it to hear them. There are steps and arches and half-walls and a giant fireplace to give some differentiation between the rooms too.
Of course we have flower beds and grow vegetables - no idea where or why this wouldn't be allowed, unless it's a shared garden and they don't want people growing food in it? I actually have heard something about the rain barrels though, and that might be a thing in drought areas, of which there are many - it could be that there is so little rain (as in my city) that they really do need all of it to sink into the ground and not be taken up in a barrel.