The answer to 'why is my ridge vent worn out' is that ridge vents can become worn out over time due to exposure to the elements. Common causes include damage from UV rays, wind, and debris buildup, as well as normal wear and tear from aging. Symptoms of a worn-out ridge vent may include cracked, faded, or missing vent material, as well as reduced airflow and ventilation in the attic.
To address a worn-out ridge vent, the best solution is typically to replace the entire vent system. This is generally a job best left to a professional roofing contractor, as it involves removing the old vent and properly installing a new one to ensure a secure, weathertight seal. Attempting to repair a worn-out ridge vent yourself can be risky and may not provide a lasting solution.