A single human body on a bike becomes a threat when they blow through stop signs and light controlled intersections, don't signal turns, don't yield or follow signs, or when they ride against traffic. Studies have shown that when accidents involving bikes and cars happen bikers are found to have been responsible about as often as drivers (https://www.npr.org/sections/health-shots/2011/05/20/1364622...). Other data suggests that cyclists are more likely to be at fault when an accident results in death or serious injury and drivers are more likely to be at fault when there's little damage (https://fullfact.org/news/are-cyclists-blame-road-accidents/).
Not counted in that kind of data are all the times drives are forced to swerve or slam on their brakes to avoid accidents. The fact that cyclists are harder to see than trucks and SUVs make them even more of a danger to drivers because they can come out of nowhere from directions drivers would never expect traffic to come from and by the time they are visible it may be too late.
I can't say if bikes are more of a danger than trucks but I can absolutely say that they are often a danger to drivers.
"At fault" is moving the goal posts. If a cyclist gets hit they likely die. If a truck gets hit there might not even be any damage. "Forced to swerve" is kind of a silly bar that ignores all the times that cyclists are forced to dodge multi-ton vehicles, again for fear of death, not scratched paint. Look at the painted lines on the roads next time you're driving and note how many tire tracks cross them.
The very assertion that they "come out of nowhere" speaks to the visibility problems inherent to driving a veritable locomotive down a city street. Yesterday, I witnessed a truck going around a curve on hop up on the curb and drive down the sidewalk briefly. This was at ~55 mph, and upon swerving and dropping the wheel back down into the road the truck wobbled and barely managed to miss the other cars in the road; a bike nearby, even on the sidewalk, would not have had a chance. Imagine being on that sidewalk; how's that for coming out of nowhere?
If there is any world in which a cyclist poses more danger to a truck, we're certainly not living in it.
Not counted in that kind of data are all the times drives are forced to swerve or slam on their brakes to avoid accidents. The fact that cyclists are harder to see than trucks and SUVs make them even more of a danger to drivers because they can come out of nowhere from directions drivers would never expect traffic to come from and by the time they are visible it may be too late.
I can't say if bikes are more of a danger than trucks but I can absolutely say that they are often a danger to drivers.