The problem with your way is the value of the treat will become less effective over time. Chocolate will lose it's allure, so what would you use then?
It's well established that, for children to feel safe and secure, they need boundaries. Making them responsible for their own decisions leads to anxiety. They can have choices, yes. But they need adults to set up a safe environment, with consistent rules and expectations. That way they know if they do XYZ then ABC will happen. They have consistency and routine in their day, which makes them feel safe.
Don't get me wrong, a high value treat can be utilised sparingly. For example with my dogs, the only time they get a pigs ear is after a groom. As soon as the first one is off the table he's at the pantry for his payment. The second one practically throws herself on the table so she can get hers. Works the same with kids. But, as with my dogs, if they get the treat all the time, it loses value and ability to influence behaviour.
A child who only ever does what they want will grow up into an entitled adult who won't be able to get along with anyone as they have never had to compromise. It would be extremely difficult for them to hold down a job where they can't control what is happening.
Or do you expect teachers to deal with the undisciplined child and instill manners and discipline? Teachers need kids to follow instructions. Can you imagine the chaos with 30 kids who have only ever done what they want to do when they want to do it? Lord give me strength!