Season 2 is the worst.
IMO, Season 2 gets way better once you rewatch the series. It sets up everything that happens going forward with the Barksdale crew and the street drug trade as a whole. I'll reframe from saying anymore because of spoilers.
As for the Sobotka's they are a story of tragic figures. Frank was just trying to keep the world he knows alive when it was probably not worth saving. He is a taxi driver trying to stop uber.
The dock workers are honest people until they aren't. Simmon uses the dying union to show you what people will turn into when they are pushed against a wall. Frank bribes congressmen and turns a blind eye to the greeks. His nephew becomes a drug dealer.
The fall of the Sobotka family is going on while Stringer is trying to turn his family legit. It is a tale of two worlds.
I get not liking Ziggy, he isn't supposed to be particularly likable. He is a frick up and plays it pretty well. He was born into a lifestyle that is dying. He shows signs of being productive (good thief, tech savvy) but he is too busy wanting to be his dad.