The problem is books three and indeed four, both of which are being covered in part by this series were about 800000 pages long, and dragged in parts for eternity before events occurred. They need to build time into the arcs, and set the plot for various things.
A slower episode yes, but not a bad one.
1 2 and 4 were swift, 3 dragged and was certainly duller. 5 tied off loads of things and gave some major reveals. Things we had hints at before, but never confirmation.
Baliesh starting the whole war with the death of JonArran, by his wifes hand, and then instructing her to write the letter. We already know it was his dagger used to implicate Tyrion in the assault on a broken Bran.
He has been playing everyone against each other remarkably well. And now he brings Sansa to the madwoman. Thankfully we were spared any further breastfeeding scenes.
Cersei is building plots of her case, but we see much more of the mother in her, trying to protect Tommen, and missing the daughter greatly now the beast is dead.
Tywin explaining to his now trusted daughter that the realm is the only way forward for house lannister as the bottomless pits of gold are now gone, and expansion and diversification is the only way forward.