Yep, kids use the overall admit rate as a marker all the time even when it it blatantly inappropriate to do so.
Some also see to expect that they should get in even at schools that reject 7/8 or 9/10 applicants.
BTW, @Wje9164be, because the 2 biggest elite privates are in the Ivy League (Cornell and UPenn) and some of the smallest (like CalTech and MIT) are not, you won’t have 50K slots in the “top 20” even if you add in the top 20 LACs unless you include some of the big schools like Cal/UMich/UVa/USC/UCLA/UNC.
@JustOneDad, didn’t you realize that there are at least 5 schools that are #1 in the country (just like there are 25 schools in the top 15, 40 schools in the top 25, etc.)?