I don’t have enough data to say how much harder it is, and it depends on the school. But it is definitely a lot harder for an International applicant from Asia, at both need-blind and need-aware schools. But not zero percent - schools still want to attract super talented kids from abroad, but the budget can be limited as is the number of spots.
Consider Amherst and Bowdoin. Both are need-blind, but they are geography aware, and they have a limited number of international students they will accept. Last year, Bowdoin had 6,500 domestic applicants and 3,500 international applicants (35% international applicants, but only 10% of students on campus are from abroad). That has jumped to 13,500 overall this year, with undoubtedly a lot of internationals applying for FA. Its regular decision acceptance rate will probably be 6%, and its RD rate for internationals could be 2%. Amherst has a similar admission profile.
Similarly, and I don’t know the figure, but I imagine a significant number of PA and PEA’s applications are coming from International kids hoping for FA because of the schools’ need-blind policy. International applicant acceptance rates could be less than half that of domestic students, not because of limited FA, but due to the sheer numbers of international applicants versus the number of international spots available.