And here again, come the misinformed people putting words into an article they didn't read to justify their misinformed viewpoints. I will add this as a Hongkonger—

Everything in the article is more or less true. Before the handover of Hong Kong to China, Hong Kong's minority of Europeans were much more active and prevalent (because they had a disproportionate amount of political power and controlled a lot of the wealth). After the handover, this special status went away and naturally, the Chinese majority took over the Government. Through the decades, Chinese investment and the power of the Chinese economy have wrestled away economic hegemony from Western companies, although American and European money still holds a lot of power in Hong Kong. Infamously, after US President Donald Trump put HK Chief Executive Carrie Lam on the sanctions list, the banks closed her accounts and she was forced to receive her salary in cash.

Nonetheless, the white minority in Hong Kong were still active from a cultural and economic standpoint, but they are leaving. These are the reasons—

• Hong Kong is autocracising. The exercise of Government power is becoming more and more arbitrary, no longer constrained by a rigid set of guarantees and restrictions. People (not limited to just Westerners) are no longer confident that the Government of tomorrow won't decide to strip away the freedoms they've enjoyed, arrest them for their political views, or seize control of their businesses. China is imposing its political ideals on Hong Kong, and China's system only works if you have complete trust that the Government has your best interests at heart. Hongkongers, both Chinese and otherwise, especially those educated in the West or in Hong Kong's Western-style universities, tend to follow the Western liberal tradition of not trusting the Government. Hence, they feel threatened when the Government starts stripping away the elements of the liberal democracy they expected, and they don't feel safe in Hong Kong.
• Yes, people see things like the Chinese national being played on TV four times daily and new laws being passed making it illegal to criticise the Chinese flag or whatever and they think "This is bullshit, why does the Government care about that?" And yes, people do think that even if you can criticise the Government doing things you don't like, the Government doesn't care about your criticism in the slightest and there's nothing you can do about it. They feel neglected and left without a voice. All you can do is complain about it over tea with your friends. People think that if you start a protest or political movement critical of the Government, you will get arrested for some trumped-up reason and the police and bureaucracy will harass you.
• Living in Hong Kong is losing the advantages it once had over other cities. For the educated professional, there's no reason to stay in Hong Kong instead of chasing higher salaries and lower costs of living in Europe or America. And plus, since that demographic is overwhelmingly liberal, they feel that the way Europe and America are governed is closer to their own political views, and they feel safe in the legal guarantees afforded by those countries' constitutions. I made a salary of 2,500 USD = 20,000 HKD a month working in IT as an intern in America with no experience. Hong Kong employers baulk at the prospect of paying me 20,000 HKD a month now. Meanwhile, I can easily find a job in now the USA with my qualifications now paying 40,000 HKD/month equivalent. Hence, brain drain. It made no economic sense for me to stay in Hong Kong.

I will, however, give a brief mention of the fact that this article mentions the exodus of white people, but it is important to note that there is also more than ever a growing minority of South Asian people (Indian subcontinent, Indonesia and Malaysia, &c.). I think it is pretty racist to not count those people as contributing to the internationalism of a city. Nonetheless, these people tend to be employed in an exploitative system of domestic labour rather than participating as genuine equals. They do not enjoy the same rights as Chinese Hongkongers or white Hongkongers and labour laws do not afford them nearly the same protections. They form an underclass, something that Hong Kong likes to sweep under the rug. More Hongkongers than will admit are openly racist to them; a slang term for an Indian person is a homophone for "a worse [person]"