If you click on the link in the thread, there's an editor's note clarifying that this paper is being used to prop up dodgy claims, for which there's no evidence. The main issue I have with the 'lab leak' theory is that I haven't seen much evidence one way or another. Hitchens' razor applies- what can be stated without evidence can be as easily dismissed without evidence. I personally don't see any issue with the idea…
Zoonotic origin is the obvious choice. As a general rule, nature is way better at evolving pathogens than humans are. The problem with this theory is we haven't yet found the wild population from which Covid originated. Now this can take time, sometimes years. But for SARS/MERS this was established relatively quickly. The other problem is the bats widely thought responsible were hundreds of miles away from Wuhan.
Since Covid has entered certain wild animal populations it's possible we'll never know.
That leaves us with lab origin. Lack of evidence for anything else is not positive proof for lab origin of course. But lab origin hasn't been ruled out either.
There are lots of variations on lab origin theories. Deliberate release, accidental release, naturally-occuring pathogen, gain-of-function reserach, the authorities knew, the authorities didn't know, etc. Given the asymptomatic nature of Covid I personally think that if this is the origin, accidental release is the most likely cause.
So what evidence supports this? The CCP's failure to cooperate with WHO investigations is a big one. Right at the beginning, WHO fell in too quickly with China's narrative too. Plus China did punish the doctor who originally raised the alarm about a novel coronavirus (who later died from Covid).
I personally think it's way more likely that China doesn't want to know if it was lab origin rather than they're covering it up. Like there's literally no upside to finding out. Every level of the government doesn't want to know or be the one responsible for screwing something up. It's a bit like the Columbia space Shuttle disaster where it was suspected a foam tile damaged the shuttle but using satellites to image the shuttle met with internal NASA resistance. Part of that was there was nothing they could do but also people just don't want to know sometimes.
Another issue: the missing coronavirus database that China had that was taken offline in late 2019. Weird timing. Again, no proof of anything. Perhaps it's changed now but as of last year this hasn't been examined by anyone in the West (like the WHO).