Even though I'm not a fan of their relationship, Scott and Allison were actually good in s1. But one thing I loved about their interactions was how Scott created a safe space for Allison and made her feel comfortable being a girl, or a human being.
In the first episode, Allison felt so embarrassed about freaking out when she hit the stray dog, because she had been indoctrinated to think she should be strong. So in her head, being strong can't go hand in hand with being a girly girl. Scott noticed this and assured her he, a guy, would also freak out and cry like a girly girl, making her know it was alright to be vulnerable.
In a deleted scene, they're driving to Lydia's party, and he asks her if she listens to lady gaga. She gets defensive, i think trying to push back to the stereotype that all girls listen to lady gaga, then he sheepishly smiles and admits he also listens to her music. Allison became more at ease and then admits she listens to lady gaga.
Even in s2, she's dealing with the grief of losing Kate, and she felt so conflicted about mourning a murderer. But he made her know it's okay to grieve because she lost an aunt, and a friend. So she's valid in her tears.
Personally, I actually feel like Allison needed Scott because he made her feel so safe and secure and valid. And it kinda pushed her to grow, and deconstruct toxic ideologies forced into her head.