Because coming from a natural source, namely other people, I can estimate risk probabilities for a range of outcomes, in the short term. Highly pathogenic viruses in general have a tendency to become attenuated as they spread, due to evolutionary pressure. In the medium and long terms, there are two main benefits to the virus versus an experimental vaccine. One is that there are no known long-term effects (aside from scarring) from other closely-related viruses, and two is that because tens of millions (or more) of other people have been (or will be) infected by it, there is enough of a population for serious focus and work to be done on dealing with it. Lastly, it isn't unreasonable to assume that practically everyone will be exposed to it anyway.

Vaccines, on the other hand, especially experimental ones, have been historically known to suffer from contamination (biological or otherwise), and result in strange, hard-to-diagnose problems. These problems are suffered by a tiny population (the experimental group), with no broad societal, medical, or research support -- which makes sense, since the highest societal priority is typically to help as many people as possible. The three main concerns with the vaccines themselves are that (a) there's no biological pressure to attenuate negative effects, (b) the biologic components themselves may infect the patient, without any point of comparison commensurate with widespread viruses in the field, and (c) the other ingredients (stabilizers, preservatives, etc.) in vaccines are often toxic in their own right. In the past it has taken many years, even a decade or more, to get it all right.