https://en.wikipedia.org/wiki/Chironomia ?

It's likely the gestures have as heavy an accent as the speech in: https://www.youtube.com/watch?v=FSTAAs1Y-38

(:futurama fry:) Not sure if codified gesture, or ancient meme format.

Could be frequency, could be magnitude of the gestures, could be the gestures are more prominent/memorable/not subtle. Probably a combo, or, it's possible that the stereotype was centered around a few prominent individuals and is not actually a trait of that languages speakers.

It is not just Italians, but latin based languages (Spanish, French) are also known to use more gestures, while Germanic ones, a lot less... eg. German, Swedish folks almost come out as 'robotic' compared to Mediterranean countries.

I was just participating in a conference over Zoom. For most people it was enough to just listen to the audio and look at the slides on their shared screen. For the one Italian speaker, you really needed to watch her hand gestures as well to get the full effect of the talk.