https://www.nhtsa.gov/road-safety/school-bus-safety
School buses are, statistically speaking, the safest vehicles on the road. Your child is 70 times more likely to get to school safely riding the bus. Of all the kids that ride the bus to school in this country, only about 5 die annually, and they don't typically die in bus accidents, they die either walking to the bus or because they suffer a medical emergency on the bus.
It is somewhat absurd to assume that a child is safer getting somewhere in your car than on a bus. You might be able to make a comfort or familiarity argument, but there really isn't a safety argument to be made here.