I think one of the reasons why I find Tuor & Idril so compelling is because they trust and respect each other so much.
Idril tells Tuor about her worries and he listens to her, and tries to comfort her (no matter how bad he is at it). This is especially interesting when compared to the highly patriarchal culture of the noldor that, essentially, has been telling Idril her entire life that her worries, ideas & hopes mean nothing.
She is never the heir, and never more important in her society than a man—even in her own father’s eyes. (Sorry for the Turgon hate but…he’s like that)
Then we have the fact that despite Tuor’s charm, he’s dealing with being a thrall, escaping that, nearly dying on the way to Gondolin and then Gondolin’s politics while being the herald for a very unpopular idea. Yet despite this, over the course of seven years, Idril and him learn to love and support each other.
(I don’t know too much about Tuor, so I wish I could add more on that section)
However, they stand out because they are so die-hard for each other’s ideas. Also, they stand out because they reject tragedy (so do Lúthein and Beren but idc rn).
Idril tries her best to bring Tuor to aman and some versions he gets to live forever. Tuor helps her with her tunnel, not disparaging her ideas, and follows her plan.
They sail together.
I cannot understate how unique they are as a couple in the Silmarillion and why that drags me to them.