Canglan is definitely one of the best written het romances I've seen. There is such care put into it, such thought into their dynamic and the way it builds, and it leaves you not only going 'love is real', but also going 'no but actually it's so good I swear.'
Like this show is so tropey, and on the surface you'd read the summary and think it's SO cheese, and it is in its own way! The show is often very silly and doesn't take itself too seriously, but then... watch out.
Because actually, this shit is serious and you WILL be bawling over these two stupid (thousand+ year old) kids, and it will hurt so good.
One thing I love about Canglan is that the problems you'd think may exist in their relationship are addressed, but in a way that's natural and organic and not like the series is going out of its way to 'make sure its healthy' or whatever. They resolve because the characters do so along the way, as two people conscious of who they are, what they stand for, and how they're developing alongside each other.
My favorite example, is of course, the famous fight over Xiao Lanhua going to Fuju Cave. The thing is, this isn't actually necessary, because the power imbalance is going to vanish anyway the minute she becomes the goddess. After all, the Goddess of Xishan stands on equal level, if not above, the Moon Supreme.
But this show is better than that. It doesn't just let this solution come to them, but has the characters resolve it themselves on their own, without a cheat code, before that. So Xiao Lanhua asserts her place as his equal, makes it clear that if they are to marry, they're husband and wife, not a little flower spirit and the ruler of Cangyan Sea.
And it's not as if Dongfang Qingcang saw her as lesser. He's made that clear as day by that point that he believes her to be the best woman in the three realms, that she deserves to be respected and venerated. He sees her as braver than anyone else in the world. He outright says this.
But he is Moon Supreme, and all his life, he has taken it upon himself to suffer for others, because he can do it, he can stand it- in a way others can't. And he knows this, because as a child, he suffered more than anyone else, and he came out alive and (physically stronger). So obviously, this extends to Xiao Lanhua and he simply cannot deal with the fact that he should allow someone he loves the CHOICE of suffering for him (and he is also not used to anyone but him making the choices). And she knows this!! But god it's just so good, because it's not about him seeing her as lesser, which he didn't, it's about him not fully understanding the balance between being protecting and overbearing, what equality is in a relationship and how to respect that, because for both of them, this is new ground, but Xiao Lanhua at least has a whole life of experience with people and relationships and emotions.
And again, they didn't have to do this. They could have just used the goddess cheat, but they did, because this story and these characters deserved that, and they were written with such love and care and passion.
I'm not even going to start with the PARALLELS. This ship has so many gorgeous parallels and I love the way they not only show the development of the relationship from both sides, calling back to earlier scenes, but they also show the way the two characters are actually similar. Because I don't really believe in opposites attract. To me, one of the signs of a well written ship is two characters who seem so different at first, but beneath it all, at the heart of who they are as human beings, have so much in common; intense love, loyalty, and yes, a desire to love the whole world* and love one person.
(*well, Cangyan Sea at least-- but in the end, also the whole world, because it's the world that she loves.)