Naming someone as the additional insured DOES NOT give them insurance for their own operation.
Naming someone or an organization as an additional insured on your policy DOES NOT mean the additional insured does not need their own insurance. A venue named as additional insured only has protection from the event holder's operation. The venue would still need coverage for their own business negligence.
Additional insured status DOES NOT give the same rights under the policy terms as a “named insured” or “insured”. For example, you may think you want to add your wedding photographer as an "additional insured". If you have hired the photographer to work at your event, naming them as an additional insured does not mean they are insured as a professional. If someone is injured because of the photographer's negligence, the photographer will be responsible for the claim.