It makes more money for the universities.
At least in the US, local (meaning in-state) students almost always get a huge discount when attending public universities (Penn State, Ohio State, etc.). People from out of state (an Iowan attending Kansas State, for example) pay the ‘normal tuition’.
For international students – they have no claim on any discount at all, and the universities have realized that they can charge FULL price for a US education, because a US degree has great value outside the US. So their international rates are significantly higher.
In addition, international students don’t qualify for state financial aid or most scholarships, the universities know theyt will be paid in cold hard cash,