Most automakers had them, they were just optional and so people didn't spend extra money on them and kept getting flung out of their cars.
Volvo had them standard, but Volvo has also never been above 1% market share in the US [1]. If a tree falls in a forest and nobody is there to hear it, does it make a sound?
The part we should be worried about is that it took 9 years for the govt to require it. 50 years from now, we'll be talking about how stupid it was that drones didn't have safety features.