Look, in a US college or university, essentially
no student ever pays for the full cost. One-third
is about the most a student pays. Instead
the institution gets money from taxes, research
grants, gifts, the endowment, and a few others. Essentially
all the money coming in is from US citizens or
US taxes from US citizens. So, the US is paying for those institutions.

If a student from outside the US gets accepted, arrives, and does well, then typically they can get a scholarship. So, who's paying for their education? Not the student, or their family. Instead their education is being paid for by US citizens or US taxes. Even if the foreign student doesn't get a scholarship, likely two-thirds or more of their education is being paid for by US citizens, not the
student.

When I was in one graduate school, a Midwest state university, somehow there were a
lot of students from India there. That university
was expensive for students from that state and much
more expensive for any students from other states.
A year there could cost as much as a new US car.
Today that would be ballpark $40,000. How is a family
in India going to come up with $40,000 to send
their child to a US university for one year?

Given the currency exchange rates at the time between
India and the US, tough for me to believe that people
in India were paying for those students from India at
out of state rates at that university. I believe I
know where the money was coming from, some special
program of the US State Department. So, it was US
taxpayers, struggling to get their own children
through college, paying for the college educations
of students from India. Why? Because somehow some
people at the US State Department believed that somehow
it was good for their effort to 'organize the world'
to take money from US citizens and use it to educate
students in a distant, poor country.

At another university, I had a graduate scholarship for
my Ph.D. The students were good but were nearly all US citizens and not very many of them. At one point a prof confided in me that the department had a lot of tuition scholarships going to waste: US citizens who were good students didn't want to come, and the department didn't like the quality of the applications from foreign students. But, whether the student was US or foreign, the cost, no doubt very expensive for the professors, buildings, supplies, overhead, was being paid for by US citizens.

Let me be even more clear: The list of the world's top
few dozen research universities is dominated by the US,
e.g., Harvard, MIT, Cornell, Brown, Yale, Princeton, Johns Hopkins, ..., University of Chicago, ..., Berkeley, Stanford, and Cal Tech. Now, they are 'research universities' which means that heavily what they do is research. The research is mostly paid for by research grants, and those are heavily from the US NSF and NIH.
The grants are very competitive. It is standard for
a university to take, as I recall, about 60% of the
grant money for 'overhead'. Hint, hint, that's how the
English department gets funded, along with the student
center, the string quartet series, the limo for the
president, the concert hall, the lawn care, the bronze statues of earlier presidents, the fountains, etc. And
that 60% number tends to come up again -- about 60%
of the budget of the university can come from such
research grants. YMMV, but look up details in the
annual reports of the top research universities. So,
it's clear: Those research universities, right down to
the grass mowing, are being paid for heavily by the
US Federal Government from tax money from US citizens.
Any student, US or foreign, however much they are paying,
is getting most of their education paid for by US
tax payers.

Then a question for US taxpayers is, why should they,
struggling to get their own children through college,
be paying for the educations of students in distant
countries?

If you went to a well known US college or university,
no matter how much you paid (maybe there are some
exceptions for students from some Mideast oil
kingdoms), most of your education was paid for by
US citizens, via gifts or taxes.