https://www.theamericanconsumer.org/2019/06/do-mandatory-veh...
https://www.theamericanconsumer.org/2019/06/do-mandatory-veh...
As a society, we tacitly accept significant death and injury every year because making the changes to avoid said death and injury would render the roads unfit for actually transporting people at the speed and volume that society and the economy require.
There are other options, for example mass public transport that (as far as I'm aware) is much safer than road travel, but the US seems unable to to invest in it seriously for whatever reason.
It is the primary concern being the most important factor in determining regulations. It simply isn't the only factor. It's a balance between safety and utility with the goal of reasonable safety.
But yes, absolute safety is never the goal.