Academic standards are kind of irrelevant when it comes to Harvard undergraduate admissions.

Harvard is a tiny university at the absolute top of the prestige hierarchy. As far as they are concerned, every serious (non-legacy/donor) applicant is a truly exceptional student. At least to the extent it can be determined from the admission materials and a short interview. They could choose randomly from all good enough applicants with no noticeable impact on academic standards.

But Harvard is not in the business of educating the most deserving. Instead, they want to educate the ones who will be successful and influential in the future, and to give them the best networking opportunities possible. The standard joke is that if the admissions officer knew that the applicant would become a tenured professor at Harvard, they would reject the applicant for the lack of success. Most Harvard graduates fail to reach that standard, but it's better to choose a likely failure (and an unlikely unicorn) over a certain failure.

PhD admissions are another story. At that stage, Harvard starts caring a lot more about academic potential. They don't want to restrict their recruitment to the US, because Americans are only a small fraction of the people with access to good education. Especially because Americans are reluctant to do a PhD due to the low pay effectively mandated by public research funders.

But foreign students pay foreign money which helps against the deficit.

On top of that many students stay in the US afterwards means a brain plus for the US and a loss their home country. These kind of braun drain is a big advantage for the US they know destroy.

Notwithstanding the unfounded isolationist argument, having international students is valuable to the university and the domestic students. A diversity of life experiences, knowledge, backgrounds, etc. results in better educational outcomes. But you probably wouldn't understand that concept.

They don't have lower standards either.

I mean they will now with a candidate pool reduction of 96%...

The rest is kinda wild. I guess Ilya Sutskever should leave? Sergey Brin would have never started Google, Jony Ive would be in the UK, Jensen Huang and Nvidia would be hailing from Taipei, Elon Musk would be in Johannesburg, Linus Torvalds would still be in Finland, the Rasmussen brothers would have launched Google maps in the Netherlands, Satya Nadella would be in Hyderabad, the Broadcom CEO would be in Malaysia...

You're beheading like 50% of the S&P my friend...

Not to mention say, the faculty of engineering at places like MIT https://www.eecs.mit.edu/role/faculty-cs/

To me places like Stanford and Caltech are world class schools that happen to be in the US. Over 90% not being American born is what I'd expect from a globally renown world class institution because that's what the world population looks like.

China has many programs to attract top global talent. If you want to fast track the transition from Silicon Valley to Beijing, kicking out the foreigners is an excellent move.

Graduate level coursework at Peking is already in English. All these scholars have to do is get on a plane.

It doesn’t actually matter if the foreign students are better or not: by having a mixed student body, with lots of cultures and backgrounds, students learn more from each other. They learn skills to work with other cultures, and ways of doing things that may be better.

Of course, in America’s future of autarky and Shogunate-style isolationism, those skills will no longer have any value, even to the elite. There’s no need to learn about other countries if everything we need is produced here and no one could ever threaten us once America is made great again. (/s maybe?)