I’m not the person you were talking to but I’m happy to spoon feed you an answer since it was so trivially easy to find: Behold, a normal sized car with a large carrying capacity and a good safety rating.

because it can’t be done at that size

it literally can be? You just don’t need to crash it into a freight train. The reason most large vehicles are so much safer is because you are significantly more likely to kill the other person in a car crash, especially if they’re in a smaller car, and if they’re not, then both you and the other party will experience significantly more impact forces compared to using a smaller car, which fun fact, makes surviving crashes a whole lot easier.

I’m not saying at that size! I’m saying that whatever size increase you need to make a reasonably safe pickup would be closer to the small extreme (the Kei) than the large extreme.

Smart gets a 5 star crash rating and is smaller than a. Kei truck. It can be done. Get Smart to make a pickup, literally just stick a bed on the back of the thing.