Yeah, I have the same question too! I can think of lots of speculative fiction with elements of mythopoeia. How much of the main narrative has to be bound up in that myth-making for it to count? How many of the story elements can feel borrowed or inspired by what we assume about the world given its genre (what I mean is, if my story takes place in Generic Fantasy World and it has a forest full of elves who are exactly what you'd expect, how much myth have I made)?
That said, I think The Concord Initiative has some powerful, detailed worldbuilding. ...Okay, worldbuilding isn't myth-making, or it's myth-making-adjacent, but it's prominent enough in this world that I feel it could fit.
Hands Held in the Snow does something interesting where it's clearly a fantasy romance, but at the same time it can feel like a grandma's fairytale to her kids. By the end the protagonists kinda feel like folk heroes, and it's interesting to look back at the story and think "wait, how did it turn out that way!?"