Ehh, it's just another part of education, let some people pay their own way. However, that requires fewer years upfront so the costs are more reasonable.

Pay their own way? Residents are already in 8 years of debt after undergrad and medical school education. How could you expect a person to keep paying their way for a total of up to 13 years of education (what it takes minimum to become a surgeon after high school in the US)?

As I said somewhere else, undergrad should be removed. But, if the current system costs X and students pay for 5% now you get more doctors.

You don't get it. The government limits the amount of residency spots. They fund the residency spots. And most students do not pay upfront, they go into debt to fund their education. Having students pay more or go more into debt will do nothing. The amount of residency spots is ultimately determined by the US govt

This is factually incorrect the US government pays for a fixed number of slots, but they don't pay for 100% of the residency slots available. Thus there is no legal limit on slots.

So who should pay for more slots?