The bicycles aren’t the hazard, the cars are.
In europe a few countries have city centers where you aren’t allowed to drive your car and some countries have seperate paths where bikes can ride.
Bikes are way better for the environment and trips around 5-15 km can easily be done with a bike without having to pay for gas or insurance etc.
Bikes also help you do excercise without having to waste time because you are doing the excercise while travelling somewhere.
Bikes and public transport are so much more efficient than cars
How are they a hazard if they can’t even do damage to anyone, the cars however weigh multiple tons and would instantly kill anthing smaller than a car if hit at something above 30kmh