I mean to be fair, the foreshadowing was there and GRRM would have done an infinitely better job at writing it than D&D did.
It’s also not clear which parts D&D added, and which parts they took out. It could also very well be that Cersei was supposed to fill the “Mad Queen” arc, and not necessarily Daenerys.
Ultimately though, the show was just so, so rushed towards the end. That is what ruined it. If GRRM ever finishes ASOIAF (a big if lol) it will be much better done, not rushed, and actually make sense.
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