Do you think colleges would even use class rank if there was no incentive behind it? Many colleges only factor in class rank because it’s a USNWR metric.
For anecdotal evidence, I know of a kid who was around my rank who was accepted to Columbia (I was ranked in the top 10%, but not top 5%), and a kid ranked lower than I was who was accepted to Penn. Plenty of kids ranked above the top 10% from my school but not in the top 1-5% are accepted to schools like Duke, Johns Hopkins, Cornell, etc, but I have friends who were ranked in the top 5% of my class who were accepted (and are attending) to schools ranked significantly lower than those such as Georgia Tech.
The smartest kid I know wasn’t valedictorian or salutatorian of the graduating class, but he is an excellent programmer and has some incredible experience under his belt in CS and was accepted to MIT (he’s attending Cornell because of the ED agreement). His average was maybe 1 point out of 100 higher than mine and his SAT scores were very comparable to mine, but his ECs and outside activities are what got him into the top schools.
It’s kind of pointless to debate this though since there are really no statistics about it. The fact that most colleges don’t publish how many valedictorians they accept or what percentage of their class is top 5% leads me to believe it’s not particularly important and they’re just using it as a stat to boost their USNWR ranking.