Correct (and, to a much lesser extent, domestic connections within Japan); this is 90% of the point. No rational actor would sacrfice O&D revenues in order to cater to the whims of US travelers who fancy SE Asia.

ICN, TPE, HKG, and the Middle East are much better suited for US-SE Asia, and the Chinese airlines will also re-enter the game (already have ex-Europe) with low fares that effectively limit the upside carriers can expect to generate (similar to the pre-covid landscape).