Alright, finally got around beating the game.
I liked it a lot, but the ending felt a bit mediocre compared to earlier highlights.
On the one hand, I'm happy enough that netiher Kratos or Atreus has to die, that each gets a distinct yet satisfying ending, and that generally speaking the game signs out in an upbeat tone. I especially like the final reveal with the mural. I'm sick of the Kill Your Boomers narrative that permeates every legacy IP since Force Awakens. Also Boy of Dad wouldn't sell as hot as God of War 5 or Kratos Does Egypt or whatever they call the next one.
On the other, the ending felt a bit anticlimactic after such ponderous buildup. Kratos knows that he will die and everything he does goes to spending the time he's got left with his son. When Atreus finds out that Kratos is fated to die, everything he does goes to helping dad avoid said fate. And in the end Kratos simply... survives. There's no cleverness involved. No bait-and-switch or Macbeth-like "sike". They play out every part of the prophecy (even when desperately trying not to, like Kratos killing Heimdall) but when they get to the very end... Kratos simply doesn't die. Doesn't even get a fakeout death that might technically acknowledge the prophecy.
I loved the one twist. Did not see that coming at all. And it made me excited for the ending, but the game was out of surprises by the end. Would've loved something clever like that for the finale. As much as I enjoyed the characters and the story kept me hooked, the benchmark was set by that one twist.
Anyway, on to 100% this.