I guess that depends on the country? In the US, motorist fatalities from crashes outnumber pedestrian/bicycle/etc fatalities like 4:1, I think? I guess that includes both motorist killing self or occupants and also motorist killing other motorists.

In the US there are probably 1000x miles traveled in cars vs on bicycles or as pedestrians everywhere except probably the top 10 metro areas. That the casualty rates are only 4:1 shows the danger that cars pose to non-car road users.

The metric you would need for this is "fatalities and crashes caused because someone was struggling to deal with their bloody touchscreen", which can be both motorists and non-motorists. I don't think anyone is tracking that.