Who should not do cycling?

Who, exactly, should avoid cycling? Is it those with certain health conditions, such as heart problems or joint issues? Or perhaps it's people who live in densely populated urban areas, where cycling can be dangerous due to heavy traffic? Additionally, could it be individuals who lack the proper equipment or knowledge to cycle safely? Understanding who shouldn't engage in cycling is crucial for promoting safety and preventing injuries. Let's delve into the various factors that could make cycling unsuitable for certain individuals.