It is really not that easy to purposefully develop a virus for the purpose of causing massive deadly disease. Mother Nature has already demonstrated that she does that quite well on her own without anyone’s help.
For a lot of reasons, I do not think that Covid-19 was engineered. Simply put, the technology does not exist to design a virus to have specific abilities. Furthermore, the fact that the Chinese routinely steal our scientific technology indicates that their science is not as advanced as ours. Normally, when we want to change the function of a virus, we insert genes from other organisms into the virus, and there are tell-tale signs that we have done this. For example, there might be a short sequence called a “multiple cloning site,” or there might be sequences from an unrelated organism (for example, a sequence from a completely different virus species, or from a plant or animal the virus does not infect).
I should mention that the SARS-CoV-2 virus contains a gene that has sections that are unlike anything known, which greatly increases its virulence. However, from reading the literature, I find nothing that strongly suggests that the mutation is not natural. It seems that the mutation occurred in bats. This is consistent with the generality that nature is much better at genetic engineering than humans.
https://newscenter.lbl.gov/2021/01/12/odd-structure-of-orf8/
https://www.pnas.org/content/118/2/e2021785118
The scientific article mentions some mutations of SARS-CoV-2 that decrease its virulence. In general, viruses decrease their virulence as a means of survival. They “want” to be maximally infective but minimally deadly or virulent, since this helps them propagate.
It makes sense that employees of the lab got infected and zoonotic transmission and subsequent epidemic in the general population took place that way. It’s the simplest explanation also. I had thought a year ago that there was a contamination of some sort in to the town, perhaps via poor wastes management, but this scenario is even more likely.
Thanks for the link to the PNAS article.