according to the guardian, in the uk, it's extremely uncommon (but not unheard of), only 1% of ped deaths involved a bike [1]. Motor vehicles are WAY more dangerous, and it kind of seems bad faith to suggest anything otherwise - cars are multi-thousand-pound metal boxes that routinely travel at speeds unattainable by all but world-record holding cyclists. The difference in kinetic energy between a car and a bike is massive.

It seems pretty logical to assume to me that you'd almost always have fewer ped fatalities if more people were biking instead of driving.

[1] https://www.theguardian.com/commentisfree/2018/mar/08/killer...