source for highlighted study: https://journals.sagepub.com/doi/full/10.1177/0300891620974755?journalCode=tmja
China also claims to have found a perfect match of the Wuhan strain in Italy predating the first case in Wuhan. I couldn't dig up the exact study so i didn't screenshot it here, but here's a link anyway for completeness.
https://www.scmp.com/news/china/science/article/3113444/coronavirus-italian-scientists-find-perfect-match-wuhan-strain
Even without that though, it's looking pretty likely that COVID-19 actually originated in italy.
edit: found the new study!
https://pubmed.ncbi.nlm.nih.gov/33292923/
We describe the earliest evidence of SARS-CoV-2 RNA in a patient in Italy, ≈3 months before Italy’s first reported COVID-19 case. These findings, in agreement with other evidence of early COVID-19 spread in Europe, advance the beginning of the outbreak to late autumn 2019
It was caught in China because they were actively looking for SARS type illness due to previous pandemics.
I don't know about Italy, but If it started in the US it would have been completely out of control before anyone realized it wasn't just a bad flu season. The only reason early cases were caught at all is because someone was conducting a flu study and went "holy shit, maybe coronovirus is here?" and tested the samples. Most people in the US can't justify the expense of going to the doctor for what they think is a flu, and we are pressured to work while sick.