Maybe numbers will help-
The general rule of thumb I’ve seen personal finance books give is not to borrow more than twice what you’ll make in a year. Let’s say your med school loans are gonna be $200,000-$300,000 (worst case scenario for most of your state MD schools)- yeah, that’s a lot of money, but most FM/IM PCP salaries are approaching that number. That’s a reasonable loan amount to take out for med school.
Some private schools I’ve seen (more DO than MD) are approaching the $400,000-thats stretching it. I wouldn’t borrow that much personally, but some people who are less risk averse than me are gonna go for it and I wouldn’t call them dumb persay.
And I think once you start approaching much over that (say the $500,000-$600,000 range)- that’s the point at which you will really struggle to pay your loans off even as a physician. Depends on your specialty of course but I’d advise my sibling/whoever not to be a doctor if it meant borrowing that much money.
If you’re a premed and you’re reading this- the beauty is, you don’t have to trust any of us. It’s just math. You can go get a student loan calculator and check it all out for yourself.