Daenerys didn't go mad

The way I interpreted it, Daenerys didn't go mad. She was perfectly lucid. The massacre of King's Landing just exposed her for what she was: a tyrant. The speech she gives to her army in the finale is the same exact speech we've seen her give so many other times, we've seen them do their ritual with the speers before as well. We've seen that scene so many times before but now the scales have fallen from our eyes and we see it for what it was, while all those soldiers stomping their speers are still hearing Mhysa ( https://www.youtube.com/watch?v=rK78w86BOQ8 ) in their heads as she's speaking.
There are parallells to the real world here as well, a Great Leader giving a fiery speech to their fanatical followers and their followers responding with some sort of salute. Those similarities made Tyrion calling her out and throwing his Hand symbol away(and ending the spear-stomping) feel really satisfying. If only that had happened irl. The show (and to a lesser degree the books, where it's more ambiguous) made you feel like part of her movement, made the audience take part in the leader worshipping, as Tyrion pointed out (almost to the point of breaking the fourth wall) when he said "WE cheered her on" even though he wasn't there for most of it.
Daenerys' story was a cautionary tale about leader worship and autocracy. They didn't need to spend seasons showing her go mad like people are suggesting because she didn't go mad. She'd been groomed to think of herself almost as a god, as something more than human, someone who's above everyone and who gets to impose her vision for a better world on the rest of the world with fire and blood. As Tyrion and Jon touched upon, almost every human being in the world has a vision for a better world, what gives her the right to impose *hers* on everyone else? And what about everyone who doesn't share her vision? They don't get to choose. And that's where you get to the meaning of this story, what it was about all along.

As for Jon, I don't think his lineage was irrelevant, I think it served a purpose, it's just most of it is happening in his head with minimal dialogue and it will be clearer in the books (though we're never getting them, are we?). The story was building up to him being king. He was almost destined to be king. People were urging him to take the throne. But what happened in King's Landing was a wake up call.
Jon didn't just realize that Daenerys was a tyrant all along, he realized the throne and autocracy was evil. Drogon showing up, looking at him, burning the throne and then looking at him again as if saying "do you get it now?" right after he stabbed her just served to drive that point home. After that, Jon's happy to go live with the free folk beyond the wall.

I thought the finale was done brilliantly (water bottle be damned) and did a terrific job of addressing the twist in e5. It's actually bothering me now when they say "the writers" ruined Daenerys' character and that it should've ended with her on the throne or dying a heroic death or something.
What came before it this season wasn't done as well imo and was rushed af. The series should've been 9 or 10 seasons.
I also think the white walkers should have served a purpose and not just been instantly defeated as soon as they break through the wall (seriously, what did they even change? What impact did they have on the world?).
And I think Jon and Daenery's relationship will feel more real in the books (or would have) where they're lonely, emotionally damaged teenagers (I think they're 14 and 15 in ADwD?) and they'll be intensely attached to each other whereas in the show their relationship has been brushed over and they're both grown adults so Jon having to stab her didn't feel as tragic, and him initially going into denial and making excuses for her after what he just witnessed didn't make any sense and made him come off as unfathomably spineless.