It's not so much the boredom for me, it's just that it lacks any believability. The central characters behave in ways no human would ever behave in their situations and get away with it. I don't know if it's bad casting, bad writing, or all of the above.
The two central characters, Marty and Ruth, are treated with a level of credibility, trust, and authority that they never earn on screen. Marty is constantly depicted in scenes with murderous druglords stuttering his way through lie after lie with the worst possible body language throughout and continues to get let off the hook for no other reason than to keep the story going with its main character. The show can't decide if it wants Ruth to be tough, cold-blooded and ruthless, or to be a lovesick everygirl who cries all the time and tries to convince a rival cartel leader to spare Darlene's life because her cousin loves her. Either way, she's not believable as a character or as an actress.