I just think Cassiopeia lacks Utility and Fun
W and R is her only utility AGAINST the enemy but they are pretty shitty. W just slows them but is easy to avoid. R takes about a second for it to activate.
Like I feel like that little second wait on her R is just for show compared to the other skills. Like with Lux indeed it takes a second but doesn't have something stupid like " oh if the enemy have their backs turned they will just be slowed a little bit" like her W can already do that why add another?
If you compare her to Syndra they both have long range skills except Syndra has a far better utility AGAINST the enemy.
While indeed cassiopeia's Q gives her movement speed, it's only for the benefit of spamming her E.
Lastly her poison doesn't even feel deadly at all, it feels like the kind of poison when a jungler smites gromp lol.