I understand strattland as a romantic ship but like. Their tragedy is so much Worse as it stands in canon. Two people in impossibly high stakes latch onto each other in a way that's maybe friends but not quite. Grace needs a familiar face on the Vat and that's Stratt. Stratt needs - well from Grace's pov it's ambiguous. but I imagine it's a mixture of someone who treats her as a person (because he can't process her as a dictator) and someone who keeps her moral compass in check. Presumably they get on well enough to spend most of their time together, but they also keep each other at arm's distance.
There is a universe where they could have become true friends. It's also not a possible universe, even if Grace never ended up on the Hail Mary. This (metaphorical) universe is one where Stratt is not imprisoned, and Grace also does not face consequences for his not-quite role as second. Maybe then, away from responsibilities, they can grow close. But Stratt (not Grace) understands that this impossible, thus there remains a Distance between them.
They hover in this space for the whole story. Closer than anyone else but just a bit further than friends. So they care for each other but they never truly Understand each other.
The betrayal goes both ways. Stratt cannot understand why Grace can be so selfish after she destroyed herself to save the world. Grace cannot understand how Stratt can be so callous and cruel when he expresses his autonomy as a human. Neither is wrong and neither is right.
The last time they speak to each other, is the first time they come close to knowing each other fully. And in that moment they let each other down.
They never get closure in-person either. They can never look each other in the eyes and say "now, I understand you and I do not forgive you. But I understand. In a different life we were friends. In this life, we saved the world together at the cost of ourselves. It was worth it, but I will carry a you-shaped wound forever."
