You could write a book on the problems with this show but you can also just boil it down to one simple aspect that captures the whole thing:
What was the point of Reva seeking out Luke? What was the possible end game there with any outcome? She kills him and... what? Vader takes her back? "Yes, thank you, I know you tried to literally stab me in the back and you tried to kill the grand inquisitor and we know we can't trust you at all but you killed this one random child that we don't care about at all in the desert, so welcome back to the team!"
What was the point of Reva seeking out Luke? What was the possible end game there with any outcome? She kills him and... what? Vader takes her back? "Yes, thank you, I know you tried to literally stab me in the back and you tried to kill the grand inquisitor and we know we can't trust you at all but you killed this one random child that we don't care about at all in the desert, so welcome back to the team!"