There are way too many playgrounds in the US with unsafe play structures and safety surfacing, with most due to neglect and not properly planning for and following playground safety recommendations we know are effective. It starts with assigning responsibility to someone or some entity capable of adhering to scheduled playground inspections, identifying and reporting any deficiencies or damage, as well as whether or not it can be repaired, or it requires replacement.
Age of playground equipment and safety surfacing can be a factor involved in examining things like loose, damaged or missing nuts and bolts, natural deterioration over time of certain types of materials like wood, plastic and metals, that can splinter, crack or rust and create hazards. Vandalism is unfortunately something that has to be contended with in many playgrounds, and it's so senseless when you consider it's placing children at serious risk of injury doing something that ought to be carefree fun. Part of any inspection needs to assess whether the safety surfacing is still performing the way it's intended, at the proper level and not damaged or degraded in any way that could pose a greater risk of injury.
Age appropriate playground equipment is crucial in avoiding injuries to younger children trying to emulate older kids, or siblings. A lot of playground injuries could be avoided by simply having adult supervision, which is always advised for children under age 6, where they are most likely to land on their face or head during a fall. Closing an unsafe playground until things are safe, is the best plan to take, and avoid unnecessary and avoidable playground injuries.