And Daenerys had been unhinged for seasons by the time she tried to burn King’s Landing.

Not quite like that. I remember feeling that she was very out of character when first watching S8. And she wasn't the only one. And a lot of storylines were just ended super abruptly, which just ruin years of built up.

But it's been quite a while since I've watched it. This drunk scottish bloke explains it quite well.