They went to the best universities in China and in the West. They lived middle-class lives in Beijing, Shanghai and Shenzhen and worked for technology companies at the center of China’s tech rivalry with the United States.

Now they are living and working in North America, Europe, Japan, Australia — and just about any developed country.

Chinese — from young people to entrepreneurs — are voting with their feet to escape political oppression, bleak economic prospects and often grueling work cultures. Increasingly, the exodus includes tech professionals and other well-educated middle-class Chinese.

“I left China because I didn’t like the social and political environment,” said Chen Liangshi, 36, who worked on artificial intelligence projects at Baidu and Alibaba, two of China’s biggest tech companies, before leaving the country in early 2020. He made the decision after China abolished the term limit for the presidency in 2018, a move that allowed its top leader, Xi Jinping, to stay in power indefinitely.

“I will not return to China until it becomes democratic,” he said, “and the people can live without fear.” He now works for Meta in London.

I interviewed 14 Chinese professionals, including Mr. Chen, and exchanged messages with dozens more, about why they decided to uproot their lives and how they started over in foreign countries. Most of them worked in China’s tech industry, which was surprising because the pay is high.

But I was most surprised to find that most of them had moved to countries other than the United States. China is facing a brain drain, and the United States isn’t taking advantage of it.

In the 1980s and 1990s, when China was poor, its best and brightest sought to study and work — and stay — in the West. Emigration, on net, peaked in 1992 with more than 870,000 people leaving the country, according to the United Nations. That number fell to a low of roughly 125,000 in 2012, as China emerged from poverty to become a tech power and the world’s second-biggest economy.

The Chinese government worked hard to keep them, rolling out incentives to lure back scientists and other skilled people. In 2016, more than 80 percent of Chinese who studied abroad returned home, according to the Ministry of Education, up from about a quarter two decades earlier.

The trend has reversed. In 2022, despite passport and travel restrictions, more than 310,000 Chinese, on net, emigrated, according to the U.N. data. With three months to go this year, the number has reached the same level as the whole of 2022.

Quite a few people I interviewed said, like Mr. Chen, that they had started thinking of leaving the country after China amended its Constitution to allow Mr. Xi to effectively rule for life. The “zero-Covid” campaign, with nearly three years of constant lockdowns, mass testing and quarantines, was the last straw for many of them.

Most people I interviewed asked that I use only their family names for fear of government retaliation.

One of them, Mr. Fu, worked as an engineer at a state-owned defense tech enterprise in southwestern China when he decided to leave. He found that after the constitutional amendment, he and his colleagues spent more time participating in political study sessions than working, forcing everyone to work overtime.

As Mr. Xi increasingly ruled by fear and propaganda, the social and political atmosphere grew tense and suffocating. Mr. Fu said he had become estranged from his parents after arguing about the necessity of the strict pandemic restrictions, which he objected to. He barely spoke with anyone and lived in a political closet. Late last year, he quit and applied for a work visa in Canada. Now, he and his wife are on their way to Calgary, Alberta.

Most of the emigrants I spoke to, explaining why they did not pick the United States, cited America’s complicated and unpredictable process for applying for visas and permanent residence status.

The number of student visas granted by the United States to Chinese nationals, long a starting point for promising future emigrants, began to fall in 2016, as relations between the countries deteriorated. In the first six months of 2023, Britain granted more than 100,000 study visas to Chinese nationals, while the United States granted roughly 65,000 F1 student visas.

Mr. Fu said he hadn’t considered the United States because he studied at a university that is on Washington’s sanction list and he worked at a defense company — both could make it tough for him to pass the U.S. government’s security screening procedure. But he said he would eventually like to work in the country, which he idolizes.

Some tech professionals chose Canada and European countries over the United States because of their better social benefits, work-life balance and gun control laws.

When Ms. Zhang decided to emigrate in July 2022, she made a list: Canada, New Zealand, Germany and Nordic countries. The United States didn’t make it because she knew it would be extremely difficult for her to get a work visa.

Ms. Zhang, 27, a computer programmer, felt the hustle culture of Silicon Valley was too similar to China’s grueling work environment. After putting in long hours at a top tech company in Shenzhen for five years, she was done with that. She also sought a country where women were treated more equally. This year, she moved to Norway. After paying taxes for three years and passing the language exam, she will get permanent residency.

Ms. Zhang said she didn’t mind that she was making about $20,000 less than in Shenzhen, and paying higher taxes and living expenses. She can finish her day at 4 p.m. and enjoy life outside work. She doesn’t worry that she will be considered too old for employment when she turns 35, a form of discrimination that many Chinese experience. She doesn’t live in constant fear that the government will roll out a policy like “zero Covid” that will turn her life on its head.

Most of the tech professionals I talked to took a pay cut when they emigrated. “I feel like I’m paying for liberty,” said Mr. Zhou, a U.S.-educated software engineer who quit his job at an autonomous-driving start-up in Beijing. He now works at an automobile company in Western Europe. “It’s worth it,” he said.

Another emigrant, Mr. Zhao, described his long and anxious journey to the United States.

He grew up in a poor village in China’s eastern Shandong Province and came to the United States for a doctoral degree in engineering five years ago. At the beginning, he intended to return after graduation later this year — China was on the rise, he believed, unlike America.

But China’s response to the pandemic caused Mr. Zhao to start questioning his beliefs.

“I can’t go back to a country where everything was built on lies,” he said.

But it won’t be easy to stay in the United States. Mr. Zhao has a job offer and will get temporary employment status as a graduate in a STEM, or science or engineering, field. That will last three years. He will participate in a lottery for an H-1B work visa. He did the math: There’s a 40 percent chance he won’t win the lottery by the end of the three years. He might have to go back to school to remain in the United States, or ask his company to transfer him to a foreign post.

“Sometimes when I think about this at night, I feel that life is full of misery and uncertainty,” Mr. Zhao said. “Then I can’t sleep.”