In case you haven’t heard: https://ftnnews.com/travel-news/aviation/naples-airport-closure-november-2026/
The good news is that Naples is just a little over an hour by high speed train from Rome.
Fourth busiest airport in Italy.
Fourth busiest in US is Denver.
For equivalent passenger numbers the US ( near) equivalents are Philadelphia, Dulles (DC) and Salt Lake City
Imagine the mess of an equivalent closure in the US.
Naples to FCO is a bit over 2 hours by rail