Some tiny thought I had was about the way Sammy comes so quickly to the "this isn't working, is it?" conclusion, after having a disagreement over something that, on a fundamental level, just needed a neutral ground for discussion.
At this point, Sammy already felt like not deserving anybody's attention and love anymore. From her POV, her family left her, Yaz left her, Brooklynn was the only one still there for her. She apparently sent care packages regularly to everybody, which apparently nobody returned the favor. As far as we know, she was the one who always knew where everybody was. Then Brooklynn left her too (death) and later found out she wasn't even dead (betrayal).
Yaz choosing Brooklynn "over" Sammy was the final proof to her, that nobody actually cared about her anymore. The last person she held out for was her girlfriend.
That's why the conflict created by Brooklynn quickly spiraled towards their breakup without more discussion. All while Yaz didn't realize this was happening, mostly due to the fact that Sammy was not honest with her about her feelings beforehand.
She was ready to just go back home, alone as before, because she accepted her lonely fate.
Season 4 will not leave Sammy and Yaz in the situation they are in right now. There has been no chance for them to properly talk about the past year, without the threat of being eaten by a dinosaur. They haven't even said goodbye to each other. S4 will not remove the before mentioned dinosaur threat, but they might come to a conclusion on what they'd be willing to do to keep going.
I know that a lot of people don't like her and say she's a useless character. IMO this is simply due to the fact that a single one-time watch of the show doesn't do the characters justice. I wanna partly blame attention span. But also just the limited runtime the show has.
Example: would a normal viewer notice that Sammy is scared and vulnerable when Yaz is around in a dangerous situation, seeking comfort in her? But when she's not with her, she's perfectly capable of fighting for herself.
Sammy, especially in Chaos Theory, is one of my favorite characters. I'd probably write an actual character analysis if I had the time and head-space for it. But I just hope she's getting a good conclusion to her story.
