There were workers in the Italian fashion industry who came straight from Wuhan. That was the whole reason they had a step-function for initial infection.
You're right that what actually matters is the number of people travelling between countries - social, rather than physical, geography - but for the most part actual physical distance from Italy seemed to be a good approximation of that, maybe with the exception of the UK and New York.
The reason why Italy was the epicenter is a bit of a mystery though. There's hints they screwed up their Covid testing and managed, pretty much uniquely among Western countries, to not actually test people hospitalized with potential symptoms who didn't have links to travellers from China, meaning that they only detected community spread when someone who did happen to have contact with someone who travelled from there caught it from someone else. But there doesn't seem to be much coverage of this at least in English-language media; everyone's focused on arguing that their country did worse than Italy because Italy was caught by suprise, whereas everyone else had them as a warning, without examining how they ended up getting caught by surprise. It's also not a full explanation. Possibly it just came down to random chance.