Just had Garen and Darius reach lvl 3...
...never was that underwhelmed by anything in my life befor. They just died imidietly, and in the few fights where they didn't die, they just got ignored despite morellos on Garen+sorc-buff
Seriously, knights(and most other non assasin melees) suck hard after the early stages, they deal poor damage, they lack CC (exept seju and cho) and their tankiness scales as horrible as on the rift. Their only use is buying your backline** just enough** time to fill their manabars...