I am Italian and have been an expat since 2010. After living in London for 2.5 years, I currently live in Hong Kong but I regularly come back to Italy for (long-ish) holidays and to see the parts of my extended family still living there.
What I like the most about living in Italy is the following:
A. I know the people: people in Hong Kong change country every few months or after a few years at most. If you make a good friend here in Hong Kong, be sure that next year most likely he/she will relocate elsewhere. I remember that after 3 years in Hong Kong I basically lost all my friends here, one by one, because they had relocated elsewhere. Cost of living is simply long-term unsustainable if you are not local and/or benefit from a first mover advantage (ie. those that moved here 20 years ago). In Italy this would be impossible: in Venice or in Milan I have the same friends living there since the past 20 years (!) and none of them would even dream about relocating abroad. They have kids, a house, a solid job: their life is positively set in Italy for good;
B. Everything is close: in Italy wherever you want to go, it is pretty close. If you live in Milan (north of Italy), in just 2 hours by car or train you can be at sea in Liguria, in the mountains of Cervinia, or in Venice or in Florence. In 4 hours you can be in Rome by hi-speed train! No need to take expensive airplane tickets and go through the airport security hassle.
C. Cost of living: things cost much less in Italy than in London or Hong Kong. I am aware that the prices are steadily increasing also in Italy but everyday stuff (as well as real estate) is still much cheaper there than in Northern Europe.
D. Warmth of people: generally, people are kind and warm, in most of your daily interactions. Here in Hong Kong you never hear unknown people wishing you a simple “Good morning” in the elevator. Ditto for London. It is not that they are bad, it is just a cultural thing I suppose, but these small things make a lot of difference in your daily life (at least for me).
E. Naples: Italy has Naples and no other Country in the world can say the same. Naples is an extraordinary city and, in this world of skyscrapers made of cold steel and concrete, they don’t make cities like Naples anymore, so much so that I consider it in a league of its own compared even to other Italian cities (and I am from Venice, itself not a bad city!) or World Capitals. Naples may be too chaotic for some, but the mix of fantastic art, exceptional food, colorful history and the passion of its people, make it completely worth it (their coffee is also on another level).
F. Food: wherever you go in Italy, you can be more or less sure that you will be served top quality food. Variety is also outstanding. Every 50 km there is a different recipe to discover, local food, a particular way to cook, some special delicacies. This is priceless and unheard elsewhere.
G. Culture: virtually every city in Italy (no matter how big or small) is full of cultural attractions like museums, churches full masterpieces, monuments, beautiful buildings, medieval walls, ancient ruins (sometimes dating back to more than 2000 years ago), etc. Nothing even comparable (in terms of density, naturally) is available for example in Asia. In my opinion, access to cultural attractions readily available completely changes the quality of your life.