Also the airlines currently operate as a legalized, unspoken oligopoly.

The current arrangement has DL profit sharing with KE on TPAC flights while only having to commit their metal to trunk routes to ICN and to Asia routes that have high business or tourism driven O&D (aka HND). Instead of putting a 763 in Tokyo for NRT/HND - SIN, they can now instead put that 763 out of JFK for an additional TATL flight or put it on something like the newly announced MSP - OGG flight where they believe they can (a) command higher ROI and (b) leverage their existing pilot and FA bases without having to also support an entire Asia based base.

More importantly the unspoken oligopoly basically puts all the airlines in a detente because life is pretty good for them all right now. So let's play armchair CEO who wants to add more flights to Asia. Here are the options that have popped up most in this thread:

1) Add frequency out of LAX -- okay but LAX specifically is where you (a) face the most amount of competition from foreign airlines which pushes airfare down and (b) despite years of trying no one airline has a dominant O&D structure in place so you're relying on connecting folks into a non-hub. Why would you waste your airframes here (especially when it requires 3 frames minimum to go LAX to deep Asia)? SQ/CX get the super premium passengers and everyone else takes a connection via HND/NRT (UA/AA) or ICN (DL) to their final destination in Asia

2) Add frequency from existing hubs (SEA, DTW, MSP) to deep Asia routes (SIN, HKG, BKK, etc.) -- okay you could theoretically put some 763s and A339s ex-SEA to deep Asia routes but then (a) you end up overflying ICN so you better be able to command a price premium on the O&D flyers who want 1-stop instead of just routing them via ICN or believe that there are enough folks booking away from DL to UA/SQ for the 1-stop flights via SFO/SEA/JFK/EWR (b) you better not have something with a higher yield for those 763s and A339s (say TATL and Australia/New Zealand flights)

3) Re-establish a 5th Freedom based out of ICN -- okay but again where are you pulling the aircraft from, where are you basing the crew, how much incremental traffic do you have from DL travelers who will only travel to SIN on Delta if they can fly DL the whole way instead of flying XYZ - DTW - ICN (DL metal) and ICN - SIN on KE metal

4) Attack the SFO hub from United -- nope not happening