Trust me in doesn’t. The biggest disadvantage as such is people mucking around in class and distracting you. However a good student will just go home and revise it. It does not matter.
Also don’t think just because a school is selective it has better teachers. The only schools which you know will have better teachers are private schools and that’s a different story... I have many friends that went and go to top 5 selective schools and there’s heaps of teachers that have no idea what they’re doing...
On the contrary I had amazing teachers in a school ranked 200+. For example my Physics teacher had a degree in Physics from usyd and explained everything in detail.
The disadvantages aren’t to the point where it’s going to hurt your atar even if you work hard. As I said in my previous post the disadvantages are really indirect.