1) We don’t know for a fact that it was ever first in animals.
2) We don’t know for a fact whether it originated in an animal in a lab, an animal outside a lab, or in a test tube and not in an animal at all.
3) Maybe the people who do know are sharing notes with Seth Rich right now.
You’re right, it has not been proven.
And that is why these opinion writers who unflinchingly repeat the CCP line “made the jump”, as if it’s totally settled, have no credibility.
This is exactly the tactic by which Obama became a natural born citizen, and global warming became settled science. Just keep repeating it as if it were true. Eventually other “authorities” will start quoting these “authorities” as evidence.
Once that happens, anyone who questions the Communist narrative will be labeled as a nut-job-conspiracy-theorist.