It's not just that the closest known virus is a bat virus. The closest known virus, RaTG13 was discovered in a cave in Yunnan, and brought to Wuhan by WIV researchers where it was sequenced, and probably other experiments done on it. WIV has also changed its story twice about the history of RaTG13, first, the date of first sequencing (They initially claimed 2020, and then changed their story to 2018), and second, they did not disclose for months that it was in fact the same virus as BtCoV/4991, which they had previously published a partial sequence of.
Transportation by lab personnel is the only way that RaTG13 is known to have come to Wuhan. Any animal transport is possible but only speculative. This entirely flips what should be the assumed scenario vis a vis Occam's razor.