I agree with everything said above!
(Even if I am very tired of all of us taking this tone with each other. I understand the frustration, but instead of being two sides of the fandom shouting at each other, we could be coexisting and enjoying the stuff we all like together, and the stuff we disagree on with only "our half" of the fandom. I hope you don't take this as a personal attack, OP, because I do get that your frustration comes from a genuine place of caring, and that's great! We all care about this fandom and that's what should unite us, not split us apart.)
I especially agree about the point about the humans Asa and Anthony being soulmates / predetermined to meet (and all the other people in the pub) undermining the entire sacrifice that Crowley and Aziraphale have made to end predetermination! That was one of the most frustrating things about that ending for me!!
Anyway, I wanted to add a few points that underline a couple of things already mentioned:
In s1, Adam had the free will to throw away his destiny by literally making himself into not-the-Antichrist in the end. Anathema demonstrated her free will by burning the (second) book that had predetermined her entire life up until that point. And Crowley and Aziraphale showed their free will by not following their sides but fighting for the humans. That was the central theme of s1, and saying that humans had no free will in that universe is a little insulting to that story, imo.
About killing and then remaking the / a universe:
There's the scene where Adam tells the Them he's gonna kill and then remake all the people, even their parents. And the Them are horrified and tell Adam they don't want new parents, they want THEIR parents.
Parallel to that, in s2 we have Job, whose children are supposed to die. And then, if Job stays faithful to God, he gets double the children! Only not the original ones, because they're dead. Aziraphale, Sithis and Job all express their absolute horror at this because they don't want new children. They want THEIR children. I'm assuming Crowley sees the horror in that even more because not only is it HIS idea to save the children - no, he saved all the frikkin goats too, because new goats also wouldn't have been the old goats.
In the face of that, I am truly baffled that s3 then turns around and says killing everyone in the universe (and that includes Adam, Anathema, Newt, Tracy and Shadwell, who fought for the universe to be saved) and then making new people in a new universe, is a good ending.
After s1, I staunchly said that I do not want Aziraphale and Crowley to kiss. Then s2 rolled around and they did kiss. We all know in what context. Now after that context, I think a kiss to resolve how they left off s2 was narratively necessary.
I see the argument that the fingers-to-lips is a mirror to Aziraphale pressing his hand to his face after Crowley kissed him. I understand. But it also gives "Amazon doesn't wanna upset the homophobes" just a little bit. At least to me.
It's not that they didn't need a kiss. They HAD a kiss. And that kiss was without consent and tragic. If they had wanted the story to be "actually, Aziraphale wanted to kiss Crowley too, it was just that the context was bad" then a kiss in s3 from Aziraphale would have cost them 2 seconds of screentime and cleared all that up.
About the ending being inevitable:
s3 tried very hard to say it was inevitable. But it definitely wasn't, even after s2. Because out of all the millions of tumblr posts, fanfics and theories, not ONE that I've seen predicted that they would kill the entire universe in the end.
If an ending was inevitable from the beginning, people would see it coming. Not everyone of course, but I would expect a good half to a quarter of the fandom to say "yeah we know how this is gonna end" beforehand.
(I'm personally not against them turning human, and I've seen this said a lot. That is not what I'm talking about. I specifically mean all of humanity and them dying.)
I am, in fact, a nihilist. And yet, this ending still felt like a slap in the face. Yeah, sure, nothing matters so we might as well kill ourselves right now. But if nothing matters, then we also might as well NOT kill ourselves right now. We might have a little fun and whimsy if it doesn't matter anyway.
But the message "if there's someone more powerful than you, then the only way out is to kill yourself" is definitely not the message they wanted to send with Good Omens. And yet, that is the message that was told with s3. And THAT is the slap in the face.
(Crowley's human doppelgƤnger then being happy, presumably because he didn't go through Crowley's trauma from the Fall, only makes it worse. That tacks on an aftertaste of "if you're traumatised, you're not gonna be happy in this life either way". I will admit that this conclusion does not directly follow from the narrative of s3, but I have heard people argue that the reason they had to die is that it was the only way to undo Crowley's trauma. To someone arguing this, I will kindly ask: What's wrong with you? Please think about what you're saying to people before you say it. You can't tell actual, living, traumatised people that they'll never be happy unless they kill themselves.)
If they "didn't die" or "died but came back", then Asa and Anthony would need to BE Aziraphale and Crowley. And I agree that that's what the writers wanted to say. Unfortunately they did not actually say it.
The only reason I know that the human doppelgƤnger are supposed to be A&C is that there would be absolutely no other reason to show them in the epilogue otherwise. But that's a meta reason. Actually IN the story, they're treated like Shax and Madame Tracy, like Nina and Sister Mary Loquatius, like Maggie and that other nun whose name I forgot. They're played by the same actor and are in Good Omens. Why are we supposed to believe that Shax isn't Madame Tracy in another life, but we're supposed to believe that Asa is Aziraphale, when we're not given a single nudge in that direction?
Anthony and Crowley even have distinctly different characters and I can't for the life of me figure out why. Because that must have been a deliberate choice. They chose to not make him like Crowley, and then said "We've done a good enough job establishing that this is Crowley, so we don't need anything else to show that they're the same". (And something something, even David Tennant said that Crowley was evaporated. But honestly, David Tennat's opinion on this is just as valid as everyone else's.)
Anyway, that's why I think the story fails at introducing them as a happy end for Crowley and Aziraphale instead of a replacement for Crowley and Aziraphale.
Plus, it depends on what, in your personal opinion, makes a person a person. I do think all our history shapes who we are. I also hate stories that clone a character, kill off the original one, and then say "happy end!! They've been cloned, so they're not actually dead!!" (If I had a nickel for every story that did this, I would have, like, 5 nickels. Which isn't a lot but it's weird it keeps happening.)
If you liked the ending, that's great!
This post is not an attack on you or your opinion! It's just a write-up of the literary / narrative reasons why this ending, for me personally, was the absolute worst that it could have been. ("worst" not as in not-happy but as in "badly fitted to the pre-existing narrative of s1, s2 and even s3 itself")
We can still all enjoy the parts of Good Omens we all enjoy, and we can seperately enjoy the parts we don't all enjoy. I'm not here to rain on your parade. In fact, I'm happy you're having a parade! I just hope you're okay with me not attending that parade.
