The endless are essentially spirits that we help in moving on to the other side and return to the lifestream.
At least, that is the feeling I get from the side quests where some have a strong enough will to remain and see their duty through, it reminds me of ghosts.
Is what happens to them unfortunate? Yes, but there isn't much that can be done about it. What we know about them basically boils down to them needing the souls of the living to sustain themselves and continue as they are.
Sphene refused to listen to reason, to cooperate despite the many attempts to do so.
Instead of finding an alternative, she chose the drastic option to ensure her people would be safe.
We didn't have enough time to deliberate and come up with an alternative, and I know people will point to the gondola scene or the play, showing that we had enough time to do those activities.
However the story does show that yes, we do have the time for it. Could we have discussed what to do alternatively? Perhaps, but would we have been able to put any plan on action before Sphene does the dimensional merge?
Throughout discussions on this topic I've seen many alternative solutions that people bring up, but I don't see what we could have realistically done to remedy the situation. Otis is mentioned a lot, his robot self, that the endless could be put in bodies like that.
I agree, we could have, provided that Sphene cooperated and allowed us the time to do so. Electrope is a technology wholly unknown to us, it would take who knows how long to figure out how it works and how to transfer the endless to these bodies. Not to mention whether there exists enough materials for something of that scale.
Not only this, but the fact that when we arrive and help the man get his wedding ring, we are told that not everyone is able to become an endless right away which shows to me their system is already failing. It's why Sphene reached out to Zoraal Ja in the first place to collect more souls. Had the gate remained closed forever, what would have happened to them? We can see how part of living memory was already in disrepair, the inhabitants having turned into monsters due to the disconnection of interdimensional fusion.
I really don't see any other way we could have gone about this given how events unfolded during the story.
Sphene and the endless are both tragic characters, and I think it's okay to feel bad for them and what happens. I never said what I have about the subject to say that you shouldn't feel bad and disregard their feelings entirely, but that we really had no other choice.
We're told insistently that living memory isn't natural, that they are going against the natural cycle of death and rebirth and through our actions we are able to let them finally rest.
Living memory is a flawed system, a bandaid to a much larger wound.
I believe it is meant to resemble a paradise for the departed, allowing them to reconnect with their loved ones but unfortunately it was doomed to fail.
People love to quote Emet-selch, and honestly it's a little bit frustrating because the actions are not the same. He too is a tragic character that resorted to an untold number of deaths because he desperately clung to what he once had and wanted it all back. In the end though, despite his plans being foiled he seemed happy and content with the lives of those in the source and the other shards.
"Remember us, Remember that we once lived."
Is exactly what he tells us, and exactly what we'll do with the endless.