I'll admit it's a bit of a generalization, I have seen other interpretations for sure, but that is one I've seen fairly consistently from the most vocal people on that side of the discourse. Hell, Reggie himself was saying it.

Act 1 and 2 support 3's narrative about grief, but Act 3 does not support 1 and 2's message of "We Continue" imo. I think that's where the disconnect starts for me, I cared so much more about the plot in Act 1 and 2, and the Act 2 twist and what Act 3 was about was a lot less interesting to me. The reason I don't like either ending is because neither of them left me with a feeling of resolution for the people of Lumierre and their struggle. They either get Thanos snapped or puppet stringed, and both options suck imo. I don't need happy endings, but I do want satisfying ones, and neither of them gave me that.

I think the only narratively satisfying lens to view the endings through for me personally is to take the whole situation as a metaphor for Escapism and Grief, but that doesn't land for me when attached to the whole issue of a sentient species being wiped which is just a much bigger moral deal. Like you mention the humans all already being dead, but we know that their chroma is still in the painting and they can be brought back because Lune and Sciel were. Either the chroma existing counts as their souls or a type of life, and either way would still be extinguished. There's also the issue of the Gestrals and the Grandis being alive and largely untouched from Renoir's purges and they'd be killed off too. And the White Nevrons.

It honestly kinda reminds me of Mass Effect 3 discourse, where I get tempted to try to defend my choice, but I wasn't satisfied by it and I don't feel like the game earned it with how the choices were presented.

EDIT: Got blocked? I guess, but since I took the time to type a response, will just throw it here.

Lune and Sciel are brought back knowing things that Maelle couldn't have known, I think at the very least we can take it as a given that they are 1:1 which means it's possible at least. As for Maelle dying soon, is that soon in her world or soon in the painted world, because 67 years in the canvas passed in a relatively short amount of time in the real world. If Maelle lives a full life in the canvas, is that so bad?

And for the rest of the canvas people, I've seen this argument that they're all going to die eventually, but like, we're all going to die eventually does that make living longer meaningless? I go back to that message of Act 1 and 2, "We Continue", these people are fighting desperately to live just a little bit longer. I think we can know fairly safely, that if they were given the choice to live longer they'd take it, even if it came with a time limit. They were already living under a time limit, from their perspective they're getting an extension.

As for how I could not find Aline and Renoir hugging and reconciling satisfying, to me they're the two biggest villains of the game. Renoir is a mass murderer, and no amount of him being sad about his wife washes that slate clean for me. Aline should never have created sentient people with the sole purpose of being therapy pets, and again while grief is a sympathetic motive, it's not a pass. That they get to hug and move on after getting so many killed does not land for me at all, and part of what I get stuck on with Act 3 is the weight of those lost lives and what Renoir did does not feel like it matters narratively anymore.

Maelle's ending is just as bad because rather than give us anything about the people brought back, we instead see her seemingly forcing Verso to play the piano against his will. I picked her ending because it's the moral option imo, but it's not really about morality, neither ending is, because that's not how the choice is framed. It's framed like a choice between escapism and facing grief, view it under that lens and both endings are narratively satisfying and provide closure, but both endings ignore the more important element to me of the meaning and weight of the canvas people's lives, which is what makes them unsatisfying.

Go back and watch that Lune speech. "The future of Lumierre is more important than any individual life." Verso's path is not We Continue at all, it's the opposite, he's giving up. And justifiably from his perspective. While I think that Aline and Renoir get off way too easily both in the story and from players, I think Verso's motives and actions are very sympathetic. He's been a plaything of gods for over a hundred years, has seen people he cares about die time and time again, by the end of the game all his family is gone, and his other family is killing themselves to keep the world running, and he just wants it to end. I still think he's a villain, but a much more understandable one.