I grant it's totally possible for this to occur naturally, at random (thank you, genetics) -- but when we haven't found any intermediate host animals and there's a lab at the outbreak location that:
Developed chimeric SARS-like coronaviruses
Conducted ’dangerous’ gain-of-function research on the SARS-CoV-1 virus, some of which had been funded by the US government (Asia Times)
Established a 96.2% match with SARS-CoV-2 and a virus they sampled from a cave over 1,000 miles away from Wuhan
Injected live piglets with bat coronaviruses as recently as July 2019
Published a paper on a close descendant of SARS-CoV-1, MERS-CoV, in November 2019
Was hiring researchers to work on bat coronaviruses as recently as November 2019
You have to imagine the very real possibility that it was just an accident.