It's just: I can go faster, if I want to (or for some reason need to). I'm really not a fan of doing the Apple thing and to infantilize the user by disallowing sideloading because it's dangerous. The discussion got dragged to compare force and impact but similarly to train tracks, highways are usually a place of motion. People don't walk around and cars are usually also fast. We counter the emergency situation such as the infamous end of a traffic jam by adding brake assistants that warn the driver to brake and then hit the brake on their own. This kind of technology seems to reduce traffic incidents so that the most danger comes from older cars without this technology.

I completely agree, that we don't need hyper cars or racing cars on the road. But the 100 mph limit wouldn't help at all in cities. There are better ways like obstacles that force a driver to slow down or routing with curves instead of straight lines.