There are far too many coincidences and the damage has been too catastrophic for this not be investigated so that it isn't allowed to happen again.
Even if can be scientifically proven that the virus was not engineered, there is still plenty of evidence that China covered it up, silenced researchers and destroyed evidence which would have helped prepare the international community, all in the effort to save the reputation of the ruling party. The WHO played a role in this as well - they still have tweets up saying that human-to-human transmission is not possible, because they trust the Chinese scientists who told them so!
I have spent time in China and found the disregard for public safety, and more generally the disregard for the value of human life, to be absolutely shocking. (As an example, when I was there, they opened the bullet train from Shanghai to Beijing. In the opening weeks, there was a disastrous collision, knocking a whole train off of a bridge and killing everybody on board. It was, quite literally, covered up: they simply covered the destroyed train with dirt, not even removing the bodies. Train service resumed shortly after [0]).