I think we're the only industrialized country that doesn't mandate some paid vacation and some paid sick leave. Most people are employed "at will" and have very little protection from losing their jobs randomly.

That opens up competition. I certainly won't say 100%, but the vast majority of full time positions have annual leave and sick leave days.

And remember there are wage/payment collection laws that protect accrued benefits - that's why (in most states) when a person leaves, they are owed their final paycheck and unused vacation days at time of termination. A person can also get as much as 25% in additional damages + legal costs if this isn't done promptly.

I understand what you're saying - but I (and most Americans) would ultimately rather have this driven by the market.