It's not that if you eat 20 Carbs or 25 Carbs a day your not going to lose weight.

You are going to lose weight but it's going to be slow. Alot depends on your body, if you exercise... stuff like that

20 Carb restriction is for induction for people on atkins

It's more like to discipline yourself to eat low carbs so that you reach ketosis quicker and start showing ketones.

This is why after induction you continue to put carbs back into your diet.