As someone with only the most basic knowledge of Cassieopea

Ive been playing for like a year and a half now and id like to think i have a fairly good understanding of how the game works, in my earlier days playing the game i remember thinking that Cass looked cool but the difficulty bar scared me away "Not yet ,young padawan" I would say to my self. But now im like a ya know jedi(Can you imagine a jedi ) or whatever and I keep seeing all these posts about Cass needing reworked and my adhd seems to get the better of because i can never come away comprehending whats going on. So i was wondering if someone would be kind enough to blatantly explain what exactly the issue with her is , Thanks in advance for your time!