do not perceive me

That the consequence of his relationship with Ruben has always been a fear based repression of who he is, converted to internalized homophobia so that he can be a man like Ruben.

But if he can accept himself, he doesn't actually need Ruben. He's no longer trying to emulate the individual Ruben is, and the bad habits he developed as a result of Ruben start slipping.

Narratively speaking, Niall's relationship with Alby changes who he is as a person. Alby is the opposite of Ruben, and his role in Niall's story inspires acceptance and reconciliation. Something he can never do when he's chained to Ruben.

Alby was the first time Niall attempted to fight back against Ruben (both physically and in court). Alby inspires Niall to break free from Niall and is proof Niall can live without Ruben.