Again, what's notable is not that people have moved on. They move on from everything.
It's the amount of thought investment into the show vs. other shows. It's staggering how much fans invested into this show vs. other shows. Like take The Sopranos. Imagine a huge Sopranos fan who watched it from the first episode. There's no way they put as much discussion into that show's ins and outs as a dedicated Game of Thrones fans.
That in itself will always be worth discussing even if the product itself doesn't merit it.
A show like the Sopranos was something to just experience and it was huge at it's time, but lore shows like GOT or Lost get people discussing theories about what will happen. Once the mystery of the story is over, it loses some appeal no matter how satisfying the ending was.
The Sopranos had few mysteries to discuss, other than maybe the Russian in the woods or if Tony was killed in the last episode. But none of those things were ever addressed in the show itself to make it a topic of discussion week to week like who were Jon's parents or what are The White Walkers up to?