Rose and Pearl are less like an enslaved and a slave and more like an abused teenage princess and her assigned lady in waiting (who was born into slavery).
Rose didn't go and say "hey I'm going to enslave this gem", she was GIVEN Pearl. Both of them were *born into their roles* and both of them suffered for it. Both only found solace from their grim reality in each other, and ran away so they wouldn't have to live like this anymore. Rose willingly gave up her power over Pearl and they even had this exchange:
Rose: "I'm going to stay and fight for this planet. You don't have to do this with me."
Rose: "I know you do. Please, please understand if we lose, we'll be killed, and if we win, we can never go home."
Pearl: "But why would I ever want to go home, if you're here?"
Rose was Pearl's home. Rose gave her a choice wether she wanted to stay with her or not, and she WAS worried that Pearl was so conditioned to care about her it wasn't a real choice but how can any one claim to respect someone's choices then go "no actually you made the wrong choice so it didn't count"?
The show went very far to make it clear that despite their starting points making this relationship very, very muddy, their love was genuine.
It was Pearl's idea for Pink to take the shaper of a Rose Quartz amd go explore her colony. It was Pearl who said
" But I've been... imagining things, even when you haven't asked me to. I imagined that I ran away and met you here on Earth, a Rose Quartz. And I'm not yours, but, I make you so happy anyway! Isn't that ridiculous?! Tell me to stop!"
Proving that she wanted to be free but she also wanted Rose, as an EQUAL, not as a superior, and it was Rose who begged her with stars in her eyes to not stop imagining.
Then we have Rhodonite and meet a pearl who was made to obey orders from someone then she fell in love and ran away.... With a ruby guard. Proving that even in their position, pearls aren't limited to care about a single person most and are even capable of fleeing them out or their own volition, if you give them enough time and experience.
Pearl could have met someone else on Earth while exploring it with her diamond and falling in love with them instead, she could have spent thousands of years only by Rose's side then go do her own thing the moment she gained freedom like Blue and Yellow pearls did, but she DIDN'T.
Because she loved ROSE as a person! As the person she became when she was free to act without restrictions, and the opposite was true as well.
Don't get me wrong, there are issues. Plenty of them. From both sides of the equation. Both Rose and Pearl were deeply traumatized and affected by everything they've been through and it made them make some bad choices and develop some truly horrible coping mechanisms and it's what led to the events of the show. Their story is supposed to be a tragedy, but the tragedy is that their love was real and they could have been happy if they were given the right tools to actually face their problems.
Look at Steven, the entire point of Future is that going through horrible stuff and not being given the right help can make anyone break down and hurt themselves and others. Does that mean that his and Connie's relationship is doomed? Of course not!