Your visa may preclude you from staying, once the undergrad program ends, without further educational plans.
Concede on the acceptance rate point, though I can’t find stats on the number that apply. I assume it is easily in the thousands though. I presume you also include in your acceptance calculation, that only around 60 medical schools even take international applicants. (A number of those are public colleges which will expect you to be full pay as an out of state student. A number of others are top schools with 3-5% admit rates.) So if you plan to be one of the 1-2 internationals that each of those schools takes per year on average, especially if you are limiting yourself to the ones that offer funding to internationals, it’s probably best to choose your undergrad college judiciously so that you don’t fall prey to premed weedout courses.
Johns Hopkins warns internationals it’s difficult. https://studentaffairs.jhu.edu/preprofadvising/pre-medhealth/applicants/special-applicant-groups/international-applicants/ and here’s an interesting note - they say “some schools may require the student to pre-pay tuition for the entire 4 years or create an escrow account for these funds.”. Penn is one of these https://www.med.upenn.edu/admissions/faq.html
Even at the med schools that take internationals, not all their MD/PhD programs will take internationals in - for example, Duke. So if that’s a plan B, it has reduced options.
Apply, but be realistic, especially about what happens in 4 years’ time.
The acceptance rate is about 14%, while the matriculation rate is about 10%. The number of internationals who applied is around 1000. This is for all non US residents, including Canadians.
I know not all MD/PhD programs take internationals, which is why I said non-MSTP.