I have/had 3 kids in IUSD and can tell you that IUSD does prepare students for college life pretty well.
None of my 3 kids had a situation where they were threatened by a classmate or were scared to go to school. They were surrounded by highly motivated and high achieving peers. It was cool and respected to be high achieving and even geeky.
Yes, it's true that it's more difficult to stand out in our ultra competitive high schools. However, if your goal is to go to highly competitive college, your kids will have to have the skills and stamina to stand out there in order to advance themselves. IUSD prepares for that.
In my oldest graduating class at Uni there were handful of kids who got into Ivys, Standford and competitive UCs. 3 got into Harvard.
I think these are pretty good stats.
Ivys are pretty overrated and insanely expensive. Any good UC will give your kids equally good education, albeit without bragging rights
Don't make Ivy acceptance a goal for your kids, just help them discover their passions and everything else will fall in place.