Apart from complying with the law, benefits include:
Improved safety / accident record because the assessment of the risks itself will make the workplace safer
That having read the policy statement, staff will know that you are serious about the issue; accept responsibility to comply with the law; do what is expected of them and know how to react to a situation
Recognition by the staff that you care for their health, safety & welfare which in turn encourages loyalty and respect
Recognition by suppliers & customers that you are a professional organisation worthy of doing business with.
The bedrock of a quality assured system
Insurance being less of a problem and indeed will be potentially easier and cheaper by not being loaded.
Enhanced likelihood of being fully covered by your insurance company in the unfortunate event of an accident
It avoids being penalised for the first offence of not having a written statement.