1. Vaccination is covered many subtypes of the virus (meaning - multiple protection), which Natural antibody is not. When you get an infection with the virus, you get an infection with one/or two subtypes, not numerous subtypes like in Vaccination. Luckily enough your body develops antibodies after infection (many people are not). thus, you need to get many times of infections in order to cover all subtypes of viruses. 

2. Vaccination is using the in-active viral particle which cannot cause/or harm to the human body. It measures carefully the amount that needs to give to the human in order to allow T-Cell /and B-Cell to react and create immunity. The real exposure to the virus (infection with the covid virus) is harmful not only to the immune system but also to many orgasms because you expose yourself to the active viruses.