> If there was a lab leak and a coverup, this meant that the Chinese government likely knew earlier and had more information about the nature of the virus and how it spread.
You're assuming that the lab "designed" it like a new vehicle engine complete with horsepower and torque specs.
Even given it was produced in a lab through chimeras and serial passage then they still wouldn't have known what they had. They wouldn't have known its characteristics in a human population. They wouldn't have known how long its incubation period was, or when peak symptoms and peak transmissibility happened, they wouldn't have known its virulence, or its R0 in a human population or pretty much anything. They'd might have receptor binding assays against the human ACE-2 receptor. That knowledge and $4.25 will buy you a latte, but it won't predict the trajectory of a pandemic.
And why aren't you annoyed at the coverup that China is doing of its zoonotic origins and that China isn't cleaning up all of the trafficking in live animals like palm civets and racoon dogs? We know SARS-CoV-1 happened, and there was no BSL4 lab to blame it on, so it was definitely zoonotic, yet still fairly unexplained, and nothing serious was done to prevent it from happening again. Now the US is blaming the WIV lab and China is feeding its domestic population propaganda about how the US did it, and still nothing is being done to address the mechanism that we know created SARS-CoV-1. There's still a known virological time bomb there that nobody is doing anything about.
And the reason why China wants to cover up the zoonotic origins and kick the can down the road is that it can use the lab leak theory to push the domestic propaganda that the US did, along with avoiding the political costs of clamping down on the animal trade. And there will be a political cost to doing that. Imagine if in 2009 that the H1N1 pandemic happened in a US pig farm and was 100 times worse, and then Obama tried to ban bacon to prevent a future pandemic.