So you want to know the story of "The 3 little pigs"? Well the 1st pig built his house out of straw, the 2nd pig built his house out of sticks, and the 3rd pig built his house out of brick. The wolf came along to the 1st house and said open the door or I will huff, n puff, n blow the house down. He blew the 1st house down and that pig ran into the stick house. Again the wolf said I will huff, n puff,n blow the house down which he did. Those 2 pigs ran to the 3rd house made of brick. The wolf said I will huff, n puff, n blow this house down. He blew, n blew, til he was blue in the face and couldn't blow it down. So all the pigs lived happily ever after, or at least til something else killed them.

Hey dust, I wonder why them pigs weren’t living in some of them government built houses , they strong like bull…..

Here in the US if you live in a “ government built”housing you are probably living in a low income housing project. Another name is , the ghetto. . Not sure how your government works but private citizens in this country pay for our housing out of our own pocket. Private contractors design and build houses to meet certain safety standards , depending on the location. To live in government built houses is living in sub-standard conditions . Legal but very frugal, not many of the amenities that most people would have in a home they built. A government built home is not a real safe place to experience a hurricane… as far as burying our electrical and telephone lines in the ground is very expensive. Some places are doing that with fiber optics but with the vast miles and miles of those lines it will take many years and billions of dollars to do so.

Cost is a big factor, also age, and the odds of it getting hit. When the twin towers in NY got hit by the airplanes hijacked by terrorist they didn't think they would fall, but the hit from the airplane combined with the burning jet fuel caused the "fire proofing" protecting the metal to be knocked lose and combine all the other burning debris cause the metal structure to melt enough to cause the collapse.
Building codes have changed a lot thru the years but not enough to guaranty that a building will not be lost, and it is not required that older houses be retrofit. The improvements are in anchoring them to the ground and putting metal strapping and braces in them. A brick or concrete house does stand up much better but there are still no guaranty and it can cost 2x, 3x or more to build these compared to a stick built house. Hurricanes are winds 75mph to 150mph sustained depending how strong the storm, but wind gusts can go even higher. But there is also damage caused by the storm surge on the coast along with very large amounts of rain that can move inland and can cause flooding. Water is very heavy and powerful and can cause a lot of damage. Often damage is caused by the blowing debris, if there was no debris the structures would have a much better chance. The good thing about hurricanes is there is warning because it's a slow developing system.

Tornados on the other hand pop up fast, many are narrow and only do damage 100ft wide or so, but others can be a mile wide. Much of the US is farm land or other open land so often the tornados don't hit any populated areas, but with more people the more likely it becomes for them to hit a house. Once again it is often the debris that causes the most damage, and it's spinning so it is really good at picking things up. Often times the tornado will lift a roof off even a brick building and the roof is designed to keep the walls from falling in, if one thing is damaged it can lead to failure to other parts.

What you call "caravans" are mobile homes or trailer houses built in a factory, not just travel trailers that people camp in, but actual homes people live in. These go down the road at up to 70mph moving from the factory to the home site, so yes they can stand up to a lot. Think about driving your car at 70mph, it can go much faster without any damage. But if you hit something going that fast it gets destroyed, that's why the debris is such a factor. A mobile home can be bought for less than $100k, a stick built home can be built for $150k+ plus the lot to put it on, a brick or concrete house is probably going to start at about $300k plus the lot but can go up very quickly from there. So you really have to force people to think about how they build and what the odds are for getting damage.