You're asserting vouchers would bankrupt public schools. How do you figure that? Maybe you're assuming that parents will move their kids to a better school, resulting in dwindling enrollment? If so, good! A public school that's not doing a great job should lose students. Let them feel the pain until they work to do better.
> When you can guarantee perfect access and perfect information, let’s talk about vouchers.
Your goalposts are unreasonable. Of course access and information will never be perfect. But they don't need to be.
When I started school, my parents were very poor. When they went on a date, they split a Taco Bell bean burrito (seriously). They had to sell a lot of stuff on the front lawn one month to make ends meet. My dad had to ride the bus to work for a while, and had to borrow money from his brother. But they still somehow managed to send me to private school (probably with tuition assistance), because they believed doing so was the right thing.
I understand a lot has changed since then; minimum wage is not a living wage anymore; many parents depend on free meals from public schools to make ends meet. But that doesn't mean the availability of other options is a bad thing or would be harmful.