ObiWan feels some responsibility for Leia too. Bail Organa guilt tripped him. This is covered in the first episode.
Reva saw Organa’s message to ObiWan in Episode 5. That’s how she knew Luke was Vader’s child.
ObiWan goes through a lot of growth through the series.
I’d also say the final battle was the best lightsaber fight since the original three.
Its difficult to even know where to start with this, because it is such a mess. But Obi wan feeling responsibility for Leia are things you have to establish much better in a show like Star wars as they do, if it was a single show with no or hardly any background to it, fine. But we know from the movies, that Obi wan is tasks with protecting Luke and Bail with Leia. But lets give them, that Bail only trust Obi wan to finding Leia, which again makes no sense as he is probably the most wanted person in the galaxy, so having him doing it, is probably a poor choice, and besides that we are talking a princess here, so Bail could have send his men or hired some of the best bounty hunters to find her, but ignoring that... Obi wan is tasked with protecting Luke and despite inquisitors being and talking to Luke's caretaker and having killed a Jedi in the very village he comes to, he decide that its is probably a good idea to leave Luke alone and go find Leia, what type of nonsense is that? Also Obi wan have lost his way with the force and have buried his lightsaber in the desert, given that he can't fight anyway, I have no clue how he imagined that he would be able to defend Luke. None of this makes any sense in regards to what we know about Obi wan and even how the story is set up.
Reva seeing that message has no connection to Vader, it is never mentioned. What they are doing with that, is similar to Reva having been stabbed in the stomach by a lightsaber when she fought Vader and it is made perfectly clear that there is no ships besides those the "rebels" have and those the empire has. Yet, in the start of episode 6 she just magically appear on Luke's planet, without any explanation to how that is possible. How does that relate to Reva? Reva is 10 years old when Anakin kills all the children, at this point Padme haven't even given birth yet, so there is no way Reva would know this. Let alone how on Earth would a 10 year old remember or even care about it, it makes no sense. Obi wan, Yoda and Bail in the movie three are close to the only people that knows about Anakin's children. So what Disney does here, is just letting Reva magically know that Vader had children, without any explanation or it even making sense.
Simply stating something in a movie or a Tv show, doesn't mean that it makes sense or is good. And it doesn't matter if its Star wars or anything else, but it becomes more difficult to do so, when its a long running show with a lot of lore in it. It would be like suddenly adding a half elf and hobbit race to Lord of the rings, without explaining how that is possible or even considering whether that is a good idea in the first place.
Obi wan doesn't go through anything, which is deserved. This whole show takes place over a few days. Yet Obi wan goes from not being able to do anything to become the most powerful Jedi in history and some of these changes occur in a few hours, again without anything establishing that it should be possible.
The last fight scene is ok, its very dark and a lot of shaking camera, the environment is rather boring and we get new magic powers introduced. That Vader can't sense that Obi wan is alive, again makes no sense, since it have been established several times even in this very show that they can sense each other.
I don't want to take anything away from people that like Disney Star wars, but to defend it as it being top of the line filmmaking, I think is to simply fool one self. It is terrible filmmaking in regards to almost everything, but especially the writing and characters are extremely poor.
Think about it, out of 6 episodes, we have had 2 kidnappings!! that is pretty damn crazy.