The really wealthy Hong Kong people saw the writing on the wall twenty years ago and started moving out. They still maintained ties to Hong Kong but many moved the majority of their assets to Singapore, Australia, the U.S., Canada, etc. Hong Kong was ceded back to China in 1997 with the agreement that they would be allowed to operate autonomously for fifty years. The Chinese weren't about to abide by that and started gradually getting their tentacles into Hong Kong government from the beginning. Even before the protests of a couple of years ago the Hong Kong government was controlled by CCP puppets. Carrie Lam, the outgoing Chief Executive, was nothing but a CCP puppet and the incoming guy is even more so.
Hong Kong is for all intents and purposes just another mainland Chinese communist city now.
And at the end of the day, it was always a Chinese city. Leased to UK but still Chinese. And the British said no to taking their Hong Kong residents home with them when they left. Abandoned them. If there is anywhere they should go, anywhere with standing to claim help, it should be solely with the British. Not our problem, this is a Chinese and a Chinese-British matter.