What I could see every couple of weeks arriving at JFK, some (international) terminals are definitely not at capacity, many factors of course, immigration, customs, ground staff, etc., but this is not something that could not be resolved if the planning is better, in my opinion … just like why quite some flights can divert to other airports yet, JFK can’t accommodate in other terminals. I see LX also added extra flights to EWR for example yesterday and today. While it isn’t nice ANZ is turning around literally half-way through and getting quite bad publicity, but the root cause isn’t ANZ.