Generally giving a squishy mage with low amounts of cc, low long ranged damage, and low burst is a bad idea.
Cass had options at longer range with her q poke being useful and defensive options with zhonyas and her ult having good synergy with her posion pool.
She has no cc to peel assassins, no mobility to out run them (+30% ms is a joke), not enough burst to take them out, not enough ranged damage to poke them out. Not enough kiting power to kite them.
These new changes to move damage to the dot aspect of her e are going to further weaken her dps.
Not a big fan of the rework, they clouded Cassiopeia's identity as a dual range mage (high range q,w) (short range e).
Now her q and w do much less, hence the machine gun mage identity.
The passive changes pretend to make her stronger but make her significantly weaker, since Riot heavily watered down her ap ratios to compensate making ap items weaker until she hits her stack sizes.
Rather than giving her pieces of her passive as she gains stacks, she gets them all at oddly specific numbers, giving her power spikes at odd times, but putting her at a huge deficit if she cannot hit these caps quickly further gating her effectiveness.
Notably the fact that her poisons are all aoe is a HUGE deficit when laning.
Since she is forced to use her poisons on minions, and she cannot trade well with her lane opponent she auto pushes the lane.
If you auto push the lane you end up losing farm or risk a gank.
Do you know how well Cass can escape a gank.... poorly.
All the Cassiopeia rework did was remove a huge amount of power from her q w and r for 80% of the game, and give a little extra power to her e.
The new passive is deceptive, unclear and makes it a pain to figure out how much damage she can do when you start accounting for items. She also has the same problem old heimerdinger had with the gated cdr.
The design of new Cass is based entirely on a false choice, you can trade from distance and do TONS of DAMAGE, but the TONS of AP you have does not turn into TONS OF DAMAGE because you have trash ratios and really odd scalings that denote your power spikes and is not a stat that is easy to see and make sense of. Or you can go into close range and do TONS OF DAMAGE but the TONS of AP does not translate to TONS of DAMAGE. Furthermore you do not have any mechanisms that are essential at close range such as tankieness, or burst, or mobility. Your dps is gated by the soon to be dot effect of the poison and your capability to stay really close. Going into close range is even more of a detriment because you can get cc'd, if you get cc'd you lose ALL of your dps. If you lose all of your dps you become dead, because Cass has no deterrents to keep players off of her if they can get to her.
The nature of Cass's kit is **supposed **to make her strong early and a solid duelist mid game, the numbers say that she will be weak early because of how detrimental her passive is when combined with her ap ratios. Her late game gameplay is terrible due to how vulnerable she is to everything that can get in range to kill her due to squishyness. Due to her low range, mages can blow her up before she gets the chance to do TONS of DAMAGE. assassins can just gapclose and 100 - 0 her because she has no burst, she only has one piece of hard cc and that is on a 60s cd at the best of times.
False choices are op
If you last hit well you still have to push the lane to grow in power or else those ap items will be worth much less than otherwise due to the lack of stacks.
If you are fed you still have to get into close range to do a good amount of damage making you a huge target and being highly squishy with no escapes, not a good spot.
You don't carry well into the late game due to your lackluster aoe and only single target dps, the time when your numbers say you should be good.
You can't get ahead early due to your inability to out trade the other carry without going all in, due to the base ap ratios being trash.
Her entire design is a catch 22 and players are rightly complaining about it.
