I think this will be an interesting learning experience for your parents. Not allowing you to apply early decision to an Ivy is senseless, in my opinion. It may provide some advantage, depending on the school and profile of your application, and it won’t hurt in any event.
But what I think they need to understand more is that, even with your excellent qualifications and what will likely eventually be a superscored 34 or 35 ACT, it’s still a crapshoot at any Ivy League school. Period. There are 3.5M kids applying to universities this fall, and those 8 schools will send out acceptance letters to something like 20,000 of them, collectively. And about a thousand of those will be to athletes. They really need to get off the idea that the Ivies are still the only elite schools. That hasn’t been the case for a hundred years, but it’s not even close to the case anymore.
I think your task, along with cranking out applications this Fall, is going to have to be educating your parents to the point that if you get into a really good public university somewhere but don’t get into the Ivy League, they’ll determine that a Georgia Tech education at OOS cost is worth half the cost of a Princeton education.