Insurance can definitely reduce risk if its cost or availability is tied to risk-reducing measures (giving the policyholder an incentive).
For example a health policy requiring health check-ups, or insisting on security or safety measures for a home policy. Or, in a weaker form, giving a discount if the customer can demonstrate they are reducing their risk.
There's also the direct intervention side: in theory, an insurance company covering people in an area for theft could lobby for improved policing. Or a car insurance company could lobby for car safety measures. In practice though they probably prefer the higher risk as that brings higher premiums...