The point I would make is that while it is absolutely true the established elite socioeconomic status/multigenerational-college families in the US favor certain undergrads, and that there have been empirical studies suggesting FGLIs and such can potentially benefit from choosing to attend those same undergrads, the Ivy League itself is just one subset of those undergrads. The same families also favor the colleges at various other private research universities, various other standalone colleges (aka liberal arts colleges or LACs), and indeed various flagship public universities. Although with public universities, the use of them by the elite families may depend on the state/region, and they may use things like honors colleges, Greek organizations, and so on to create a sort of selective elite within the overall university.
And some of that is a moving target over time, with certain colleges having fallen or risen in favor among those elite US families, the importance of Greek organizations fading (or being entirely eliminated) at some colleges, and so on.
My experience participating in online conversations about college admissions for over a year now is that a lot of high numbers kids unfamiliar with this complex web of elite undergrad programs sometimes take an avoidable boom-or-bust strategy when it comes to their lists. They include only the most famous of these undergrads, typically only the ones at research universities, such as the Ivies or private “T20s”, which are typically also the hardest for admission. For their “safeties” and often “matches” and such, though, they then pretty much ignore all this. So there is a big gap in the nature of the undergrad programs between their reaches and their non-reaches.
OK, then some get into an affordable reach, so fine. Others, though, don’t get into one of their reaches, and then they might end up unhappy having to “settle” for one of their non-reaches. And others get into one or more reaches, and yet it proves unaffordable for their family, so they again have to unhappily “settle”.
All this is avoidable because if your numbers are good enough, there are likely programs also favored by elite US families that will want you, that indeed might want you badly enough to throw serious merit offers your way, and yet that are not as famous as the Ivies/T20s. Again these could be other private research universities, LACs, or certain publics (and possibly honors programs within those or other publics).
Indeed, everything is a sliding scale, and in every selectivity/affordability range you can find colleges more (or less) likely to be favored by elite US families. And in somewhat of an ironic twist, recent changes to the US News methodology, as well as other new rankings that have been published by popular media outlets, have actually started to de facto punish these colleges for having too many kids from elite families, and not as many kids from lower SES families.
But the empirical studies suggest it is precisely those colleges which are the best bet for serious upward mobility for the lower SES kids who do attend! You have to make it affordable of course, but if you can, then, to be very blunt about it, it is a good and not a bad thing from a mobility perspective if there are more kids than usual from elite families at the same undergrad.
OK, this has gotten very long, but my point is unfortunately these new/modified rankings are kinda encouraging that boom-or-bust mentality. And of course the well-established, multigenerational elite families are not going to be unduly swayed by any of that, but other kids might.
But you, meaning, the OP, can avoid all that, including with our help. Because again to be very blunt about it, there are a lot of people here who from their own family experiences know quite a bit about the elite undergrads beyond just the few most famous you will find promoted by the popular media outlets. And we can help you navigate all that in a far more nuanced way.