re: I rewatched "Blackwater" last night.

it's not that there wasn't action and it was dialogue, it's that 3 episodes worth of dialogue didn't really service the progression of the story nor did we need that much of it to inform the upcoming plot developments

take jon:
episode 1 stands around talking and sansa is undermining him...all about the umbers and karstarks

episode 2 stands around talking about whether he should go to dragonstone. reinforces sansa is undermining him.

episode 3 goes to dragonstone...won't bend the knee but gets permission to dig dragonglass

episode 4 still on dragonstone...won't bend the knee, still hasn't started mining dragonglass, takes a walk with daeny (with whom he has zero on screen chemistry) in a cave to tell her something we already know.

wht made those episodes so boring is that the exposition serves to inform the other characters about stuff we already know. how they handled the stark reunion was much better...sansa, Brienne, and every major character at winterfell gets caught up on arya's character visually by seeing her fight rather than expository dialogue retelling what we've already seen. so it updates the characters being reunited and isn't boring for us...and it's quicker and more effective. jon and daeny, they've just had the same conversation like 3 or 4 times and it's boring.