There's no way Yangyang is ranked that low on the Rap rankings (lower than Lucas, really? And Lucas over Hendery?). I would put him on third place, hell, I can even get him tied with Taeyong at second. Taeyong raps well but his pronunciation is very hit or miss and he has this tendency of chewing his words (if you think of a Taeyong verse, you always know how he will deliver it without even hearing the song).
Yangyang, on the other hand, knows how to play with rhythm (you know how he is influenced by western rappers with his flow) with appropriate aggression and clear diction. He, along with Mark, is the most technically skilled rappers in NCT. (See exhibit A: Leonidas)
He's even breezing Korean rap even if it's his third/fourth language. (See exhibit B: Him taking over Taeyong's rap on Light Bulb)
https://drive.google.com/file/…qsgL1XHOT1-9Xp4CLrj2/view
I could go on with his resume (there's a reason his rap parts in WayV's recent Awaken The World album has been applauded not just by czennies) but I won't since it would take me hours to put them all here. The only thing that he lacks for now is exposure and more song/rap credits under his belt.