Also remember that AA and UA have a bunch of 787s and other long haul planes that are collecting dust if there aren’t places to fly. For AA and UA, they probably figured it was worth the utilization to try and fly these routes. Delta OTOH is retiring their 777s and there aren’t enough A350s to backfill what was being flown.

That all being said, in most cases DL sees more value in flying a focus city to AMS/CDG than a hub some exotic location anyway. In the PreCovid era, Delta made a lot of money flying boring routes. It has yet to be shown that flying flashy routes will move the profitability needle for Delta PostCovid either.