At best, it wants to be a typical "vengeance is pointless" type story, but the ending just shits the bed so completely and loses all the focus of what this story is even about. Is it about learning to forgive? Has notions of that but nothing about it adds up with any real thought.
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TLOU2 is the case of a director who wants to prove how much smarter he is than the audience by challenging the audience in a new way...and the result is a product that winds up saying nothing in the process. And what little it does say is completely contradicted by other facets of the plot.
I think that is the vibe I get above all -- "I'm smart!-- though I also agree with your more charitable point that ND was trying new things and didn't want to make another cookie cutter game.
The reason I found the first game so endearing was those tender moments with Joel/Ellie, and I think they got that right in 2 without simply repeating it. That said, I think my criticism or critical attitude may first apply more to a broader thought I've had about media at large: I'm bored of this equivocation of adult/mature = realistic, and realistic = grittier/"dark." If you don't like something which is bleak and violent, you're either a child or an artiste!
I may just be burnt out on that approach, and this is an unnecessary victim for my current tastes. I was thinking about Shenmue (surprise) while playing this: it has dark moments, but it feels more like a planned arc (perhaps because it is, hah). TLOU2 feels more like a effort simply to be more bleak for bleak's sake, even if that means destroying character relations or possibilities of hope. We may have been spoiled by Shenmue, for better or worse, by having a simpler (to your point), ergo more compelling revenge story.
Secondly, I think there's a pacing issue with trying to force us to like this new character too much (to keep it spoiler free). Two people saw an animal related place! Two lost someone who matters! Two were pinned down and screaming "I'll kill you!"
Overlaps-- a video game first. It feels a bit ham-handed.
To your point of challenging the audience, there's a difference between "let's develop a game where perspective blurs who is/isn't the antagonist" and "look what I did, I shook up the dressing jar." This feels much more like the latter.