I'm not sure about 3 seasons, but yeah, it needed more time to cook. I think the acceleration was twofold. The obvious is that they ran out of source material to lean on and just didn't have the chops to keep up. The other is something I picked up on I think my second watch through, and then specifically looked for it on the next watch: in early seasons, a lot of the cuts to different locales are also jumps forward in time as well. By the time season 7 happens the list of locales is greatly truncated, and the cuts become more and more jarring. I think my least favorite sequence in the entire series is the wight hunt beyond the wall. We gets lots of leisurely walking and talking scenes. Then shit goes down, Gendry runs back to Eastwatch (covering who knows how much ground before collapsing), then the raven to Dragonstone, then the winged cavalry arrives... days' worth of (in)action all in the space of like 20 minutes. It feels like it was on fast forward, and I think that's due in part to the lack of available locations to help mask the jump cuts.

And then season 8 did season 8 things.