Based on available information, it's clear why the most accepted hypothesis is that the virus originated in animals and spread to humans: "It is clear that the genetic sequence of the virus is that of COVID-19," says Eyal Oren, an epidemiologist at San Diego State University. The -19 virus is similar to other coronaviruses found in bats," he said.
https://www.nationalgeographic.com/science/article/what-you-need-to-know-about-the-covid-19-lab-leak-hypothesis