Do you mean for passengers headed to destinations other than the US? Or do you mean other carriers servicing Abu Dhabi to the US? Sorry, not sure I am clear on your meaning. I was referring to the ease of US immigration and customs when going thru Abu Dhabi, as opposed to AMS or LHR.
Many times on Etihad. Good hardware, service and food. Big benefit for travelers heading to the U.S., you clear immigration and customs in Abu Dhabi, so you arrive in the U.S. free of further formalities.