it just seemed LAZY to kill them rather than work out any kind of real resolution for their arcs.

My thoughts exactly. His formula is starting to look like a way to write books with collections of dozens of half-stories.

Jon's death wasn't tragic in the literary sense, it just kind of sucked. He did pretty much the best he could have with his experience and circumstances. He didn't fail as a result of personal short-coming or hubris. The threat of treason was always there and didn't come as some kind of major surprise. Neither did taking him away given what we know about how Martin writes. "And then he made a mistake" isn't an interesting conclusion to his story. Even Oberyn's death had more literary tragedy incorporated into it, but was still an abrupt end to an otherwise interesting character arc.

It feels less like Martin trying to capture reality of mortality and more like him just getting bored of writing for certain characters before killing them off and coming up with new ones. The larger plot is suffering as a result because there's no real point of focus. Sure Aya's story is cool, but it's a tangent from our major concerns in the earlier seasons and even presently. Reek and his chance for redemption are interesting, but they don't tie in thematically or narratively to the larger story. There's no larger thematic arc that the character conflicts and deaths are serving to move forward. Nobody cares who sits on the Iron Throne if we're not invested in the forces struggling for it.

The biggest point his story drives home is a rejection of fatalism. These characters genuinely believe, often with good reason, that they are fulfilling their destinies. Random chance and forces out of their control cut them short proving them wrong. Life is harsh. Nobody is invincible. The good guys don't always win. Sure. Those realities are precisely why we're drawn to fictionalized and embellished accounts of real events, BECAUSE IT DOESN'T MAKE FOR A GOOD STORY.