There is surely some freedom in being able to set whatever policies you like at your company without having a federal entity stipulate you give each employee X

There is surely some freedom in being able to set whatever policies you like at your company without having a federal entity stipulate you give each employee X days of paid vacation. If you want to heavily incentivize a cultural shift towards more vacation time for US employees, I don't think a federal mandate is as attractive as just an economic incentive. (Tax break to companies where X% of employees take more than Y days per year etc)