but like that implies a direct less virulent ancestor that traveled all way to a wet market in Wuhan and then somehow it did not evolve independently within Italy into a more virulent strain until it was reintroduced back into Italy after the Wuhan outbreak.

Could just be the lower population density.

Also the "Italian" strain (March2020) was found first in China too. It was just a tiny proportion of all cases, probably because it wasn't able to penetrate further into the Chinese population, and instead spread to the west.

It was probably quickly limited in China due to a mix of prior immunity, mask wearing, and actual lockdowns (all of which were lacking in the west)