If you are only intending to travel to Europe there is no need to purchase worldwide travel insurance. But be aware if you intend to purchase and annual insurance and you have not decided on a second holiday location, for a few pounds more it may be costs effective to have a worldwide policy.
There are other considerations to make rather than jut medical treatment. What would you do if all your credit cards were stolen, or all your cash? A medical travel insurance policy can help you with these types of issues, to ensure your holiday trauma is at least reduced and be covered financially.
You are just as likely to have an accident or become ill on a foreign business trip as a foreign holiday. However many take business trips alone and do have the support of a family around them should they become ill. At least with medical travel insurance you will have help at the end of the phone and be covered financially for medical treatment.
Look out for any age restrictions to family policies that included children. Some policies may say that you require an adult policy for a 16 year old, even if they are still at home and at school. Some policies may allow that child to remain on the policy so long as they are at home and not in full time employment. If you have children at this age, you should check the small print.
Not being able to speak the language can be a real problem when using your medical travel insurance whilst abroad. Often your chosen company will have English advice at the end of a phone to help you through the situation.