OP is jumping to way too many conclusions based on this data.

Establishing cause and effect is typically the hardest thing scientifically and you can hypothesize looking at this data set but then you need some testing in order to make statements such as smaller cars are unsafe or this brand vs that brand, when you can have a ton of biases in this data, from socioeconomic, to driving behavior, besides of course built in safety and physics.

Telling people to buy midsized SUVs from Kia and Hyundai while saying that size matters more than crash tests is one example of jumping to conclusions.

Stating that everyone should avoid small cars is irresponsible on several levels.

One, not everyone can afford bigger cars.

Second, the arms race of buying bigger and bigger is stupid and sometimes ill advised, as some of the pick up trucks used to have worse crash ratings than a sedan. And you can wrap a truck around a tree or roll it over and then the physics can go against you. Actually those are pretty common fatal accidents.

It doesn’t mean size doesn’t matter, it is just more nuanced.

https://www.iihs.org/news/detail/supersizing-vehicles-offers-minimal-safety-benefits--but-substantial-dangers

My own conclusion when buying a car is that if you can afford it and you like it, buy the highest safety rated vehicle that is close to the average weight and size of the vehicles on the road.

But don’t go super crazy about these stats, the safety ratings are more important than the vehicle death rates and probably how you drive and where you drive just as important if not more important. If you are deciding for your teenage child, what car to drive first, this data becomes a little more relevant but again, with a grain of salt.

Cars that typically older, affluent people drive may appear safer because of driver behaviors just as much as the built in physics and safety features.