Curious which routes is UO dumping capacity to the extent that it's forcing foreign airlines to retreat?

They've traditionally been heavily focused on Japan, and the Japanese carriers have little interest in Hong Kong over the years, even before COVID. They can't even match CX from their biggest cities, let alone think of connecting from the secondary ones that UO/HX/Greater Bay are targeting now.

I also don't think the recent slew of new routes to China are stopping Chinese airlines either.

Are SE Asian LCCs such as AirAsia and Vietjet scaling back HK?