That list doesn't include cities where the local train (subway or street rail) system connects to the airport, which seems odd. In my experience it's way easier getting to the into the city using local rail compared to dealing with parking, rental cars, traffic etc.

The only downside is almost none of these systems are in operation 24/7, with the exceptions being NYC and Chicago. If you have a very early or late arrival / departure, you just can't use them at all without waiting several hours at the airport. I wish more cities could add reduced frequency night service, something like maybe 1 train every hour or hour and a half.

As a somewhat cherry-picked example, if someone in the southern part of my city wants to take a train into the city center, the last good route with only one transfer leaves at 10 pm. At 10:40pm Google maps suggests a route with 3 transfers that takes almost twice as long (and includes the commuter rail which is a separate, more expensive ticket). The last possible option is at 11:40 and takes 3 times as long as the normal route. If we want people to use trains and subways, the service hours have to be greatly improved.