Wouldn’t a better system have more options with different approaches rather than a single lowest common denominator?

Just from a scientific perspective, more experiments that are able to learn from each other and adapt things they see working elsewhere into their approach should naturally lead to constantly improving schools.

A single lowest common denominator that nobody is allowed to escape from is doomed to failure by comparison.

Vouchers aren’t about letting the privileged few opt out, not more so than the current system anyway. And shooting down vouchers without a better plan for improving the current system is just prolonging a system that is bad for everyone (mostly the poor).