None of the bats they claim it came from were sold at the market. Meanwhile, they're tracking down every bat strain they can find and collecting them at the Wuhan lab.
Carelessness in handling would be the root cause whether the virus was manipulated or not. You provide zero evidence on the most important point.
Now, to the more conspiratorial point. UFO pyramid-shaped small drones hounded a US destroyer group for many hours. Any drone flyer would tell you that drones that shape are heavy and even stripped down ones don't fly for dozens of hours.
By the numbers, that requires a huge leap in material science and energy storage. This was not too far from a base that does classified research, so I doubt the cause was more than human.
The military really does keep a generation or two of technology to itself in every area it can. If they did make a breakthrough in quickly modifying viruses, would they publish it in a paper? No more so than the NSA would immediately publish their discovery of differential cryptanalysis. It became public in the late 80s. IBM kept it secret since the early 70s and the NSA knew about it long before that. That’s probably because the NSA employs the lion’s share of mathematicians in those areas (which also makes recruiting more top scientists easier).
Other countries do the same. If Chinese scientists discovered a faster and more natural looking method of manipulation, what incentive would they have to publish a paper? Their only incentive would be to hide it as much as possible and use it as a material advantage in the upcoming and growing conflict with the US.
I believe it was probably naturally discovered and leaked through carelessness, but assuming they couldn’t possibly have had a breakthrough when other countries obviously have in many other areas seems overly confident.