If every person was driving an articulated truck then there would be more deaths, caused not just by collisions and poor driving but by emissions too. We’d need bigger roads too- its unnecessary for everyone to do this.
To get away from this you'd have to completely redesign US cities to have people living in them instead of significant numbers commuting in from the suburbs. To begin with you'd need a massive amount of new higher density housing, the construction of which is currently inhibited by building codes where not outright prohibited by zoning. Trying to solve the rest of it before you do that is going to face massive opposition, because you'll be trying to make it harder to have a car to people who still can't realistically avoid having a car.
That's the point. Diligence won't save you but crumple zones might have.
It's also not obvious that most collisions being with cars isn't just because most other vehicles are cars. If two motorcycles collide with each other at high speed, the damage they do to each other isn't your problem, it's the resulting loss of control and the damage to your body when you impact the pavement.
> Letting cars drive on pavements isn’t permitted for the same reason e-bikes shouldn’t be in traffic (or on the pavement).
But then you're stuck between three bad options: You have separate roads specifically for e-bikes (implausible), you put high speed e-bikes in pedestrian zones, or you limit the top speed of e-bikes to something safe for pedestrians and then people go back to buying cars because e-bikes are too slow.