I heard from a Linux youtuber a while ago that Distrowatch rating are mostly a rating of "curiosity", based on the number of times the page for such distribution had been consulted on their website... And that would explain the rating for CachyOS since I saw some famous Linux youtubers who labelled it as a very stable, perfect (almost magical) arch-based distribution which would be the most performant for running video games (despite some other youtubers made benchmarks proving it's not completly true, even if it has great performance anyway). So, probably a lot of users knowing distrowatch decided to take a look at it and helped rising CachyOS' spot.
BUT I'm not 100% sure of it. I'm telling that just from my memory of what a Linux Youtuber said, so I can't tell I'm really reliable on that explanation.