Good Omens and the end of things
Spoilers for the end of the show (and the book)
Okay, I think part of the issue people are having with this ending is that Aziraphale and Crowley, as characters and as a relationship, are compelling for two (fittingly) contradictory reasons:
As embodiments of the status quo. The image of them as two immortal people who've been wandering the Earth for 6,000 years, always looking and acting generally the same despite all the many, many changes happening around them, is a delightful one. For it to be so delightful, their relationship necessarily functions in planetary orbit—keeps them apart, because once they intersect, that's it. Show's over. At the same time...
We've had this image of the two of them sharing a cottage in the South Downs, essentially retiring from all the wandering, for like... decades. This is also delightful, because it's more conclusive, and we all like resolution. And also, because the orbiting makes us anxious. "When will they stop dancing around and settle down?" we ask. We want to see them happy.
This puts any writer hoping to end the story in a difficult position. Many people (myself included) like the dance. Many people would rather they settle down. There's no great way to do both. Them being immortal is central to the first, them accepting their humanity (accepting, essentially, the fact that all things must end) is central to the second.
Now, the book actually gets away with doing both because it has one big, consistent supporting cast. You have Az and Crowley at the Ritz (status quo—Crowley literally shrugs off his attempts to get a Definitive Answer in favor of doing what they've always done) and Anathema/Newt burning Agnes's second book of prophecy (rejecting the status quo) and Shadwell/Tracy (things ending as you always knew they would) and Adam, who, true to form, embodies all of these things at once. As the very last lines of the book tell us:
"If you want to imagine the future, imagine a boy and his dog and his friends. And a summer that never ends ... imagine a figure, half angel, half devil, all human... Slouching hopefully towards Tadfield... forever."
There will always be a summer, always be a boy and his dog and his friends, always be humans being messy, forever. Even if it isn't the same summer, the same boy and dog and friends, or the same humans.
The show is in a tricky spot because it dropped much of the main cast to focus on Aziraphale and Crowley. Moreover, the show is in a much, much trickier spot than many a fic writer for the simple fact that it has things it actually wants and needs to say. It's always been a philosophically, narratively, and emotionally dense story, despite the breezy way it was written. I worry the second season may have misled people in that regard. The fact is, a perfectly happy ending would've been doing the book a disservice, because it's always been about the messiness of stories and of the people who tell them.
Back to A and C. They've been on a slow descent towards humanity for the last 6,000 years. That's what makes them special. The thing preventing them from settling into their relationship has always been the fact that they're NOT human. They're immortal, and they want to keep things interesting. They're from opposite sides, too, which means very little in practice but the fact is still THERE, making things awkward. What can ya do?
Well, you can make them human. Only then can you get a philosophically, narratively cohesive "cottage in the south downs" type ending. The whole point is that only humans can have it both ways. They're so special because the good and the bad, the angel and the demon, only get to co-habitate in humanity, no matter how close certain outliers might get. Good Omens just really, really likes humans.
And humans, fortunately or unfortunately, die. Each and every one of us. Do the lives we lived once we die stop mattering? Many billions of us have and will pop out of existence, and eventually all the details of our lives, the love stories and tragedies and adventures, whole families and lone drifters, wonderful people and terrible people, are forgotten. Doesn't mean it didn't happen. A final quote, here, and the last lines in the book regarding Aziraphale and Crowley:
"They went to the Ritz again, where a table was mysteriously vacant. And perhaps the recent exertions had had some fallout in the nature of reality because, while they were eating, for the first time ever, a nightingale sang in Berkeley Square.
No one heard it over the noise of the traffic, but it was there, right enough."
It's almost like this has always been what Good Omens was about.
Anyway, in my opinion, if you actually care about the story as a narrative, with literary obligations to philosophy and theme, you have two options: read the book and be happy with that ending, wherein A and C keep on dining at the Ritz forever, or watch the show, wherein A and C cease existing as they were and get, at last, to rest.
And if you don't care about any of that, you can read fanfiction. That's what it's there for.
