Le Great Handsome Oppressor wrote:
their relationship, their "experience" as Garnet has (in my view) overtaken their whole life and hurt their individuality.
I would argue directly against that, honestly. Their experience as Garnet is what made them even consider their individuality in the first place. Until that happened, Sapphire didn't even know she could have an effect on the future, and Ruby was just a faceless soldier in a thousand. It was becoming Garnet which made them both realize they could be something different, because as themselves they were stuck in the roles that their society had laid out for them. Garnet isn't a role they're stuck in, Garnet was a choice they made, and being Garnet is so important to them because of it. It's why they both got so upset when Pearl tricked them into becoming Sardonyx, they consider fusion to be something that let them break free of being used like tools.
And on top of that, Garnet is a much more balanced person than Ruby or Sapphire. They both, as individuals, have personality issues that won't be fixed via just character development. No amount of it would make Ruby less of an emotional hothead, and it wouldn't make Sapphire have an easier time caring about the present. To a point, the implication seems to be they're bodaciously designed to be that way, like how Pearl has an incredibly difficult time moving past a servitude role because that's exact reason she was made. Garnet takes those extremes and allows them to mix, which helps them both overcome issues they have as individuals and end up better for it.
So Garnet doesn't seem to harm them actively at all, she's a representation of their own ability to break out of their place in society and a way for them to become better individuals, not a wall against it.