Insurance is based on a concept of risk transfer. This means that the individual pays a premium amount that insures that if something were to happen, the insurance will provide a benefit to compensate the policy’s beneficiary. The amount paid in premium is low relative to the potential benefit that is paid. The insurance company rates the potential for loss and prices its policy accordingly so that it is able to pay if that loss occurs. The higher probability that a loss can occur means a higher premium. Applying group underwriting principles to travel insurance helps provide a product that is low cost and pays a uniform benefit.
How old you are, how physically fit you may be, whether you smoke or not, are all rating factors or variables that are not important to issuing travel insurance. None of those factors has an impact on a plane taking off and landing and the likelihood that a crash will occur. That the instances of plane crashes are so low suggests that very limited factors need to be considered when pricing travel insurance.