Jean Smart, as always, is amazing. She makes Deborah, the difficult character she portrays, sympathetic, believable and intriguing.
I cannot say the same thing about Hannah Einbinder's character Ava, who is totally unlikeable and annoying. If I was Deborah, I would have fired her in the first season.
Not Hannah's fault, who is very good in the role, but the writing keeps making this main character so self-involved and cringe-worthy that I stopped following the series in season 3.