"most plausible theory" according to whom? It's not a theory, it's a hypothesis with little tangible but evidence due to the nature of chinas control. It could have happened, it may not have. The problem with lab leak discussion on YouTube/Facebook is it was heavily associated with politics, and incredible unsubstantiated claims. "Experts" from nowhere, hired degrees talking about a lab they know nothing about, anonymous and convenient unheard of "researchers" supposedly "exposing the lab leak". The disinformation was incredible. Even if lab leak did happen - very few had the actual proof or good arguments to back it.