To me there's a impedance mismatch between cars and bicyclists. I have known about 2 or 3 people in my life who have died in a biking accident -- one of those people I really liked as a kid.
On the other hand I have seen bicyclists (also electric scooters) riding at high speed on a sidewalk shoot out quickly into a low visibility intersection. If you were the driver at the wrong time wrong place you would hit that bicyclist, and probably feel bad about it.
Leisurely biking on the sidewalks I think is fine, but above a certain speed the bikes should be on the road obeying normal traffic laws.
On the other hand I have seen bicyclists (also electric scooters) riding at high speed on a sidewalk shoot out quickly into a low visibility intersection. If you were the driver at the wrong time wrong place you would hit that bicyclist, and probably feel bad about it.
Leisurely biking on the sidewalks I think is fine, but above a certain speed the bikes should be on the road obeying normal traffic laws.