Basically, BOTW is "poetry" because it is heavily vibes based, at a time when a lot of games are "story" based. My most memorable moments of BOTW are exactly what you described, standing on plateau watching the sunset, walking towards hyrule castle in the rain, finally ready to face Ganon and the zelda theme starts to play, etc, etc. Not specific story reveals but the moment to moment feelings that originate organically from the world and the unscripted interactions and events occurring within it.
My 2 cents: TOTK perfected the exploration part of BoTW and completely failed on the story part.
So many times during TOTK I was thinking to myself "Are you still talking?" and the main quests are extremely clunky. I think its in Lanayru Region main quest where you are just acting like a walkie talkie walking back and forth between two people.
But then you have the quest for the tears and memories. You end up in a temple with an old stone map, that you can take a picture of, and then match the roughly outlined map with your own to figure out where to go and explore next. That is so much more fun than following a red dot and an arrow on a map like every other game!
Exploring the depth was also a lot of fun, although I felt it was too big to explore completely. But I've read that many things in BoTW and ToTK is not meant to be 100%ed, which is also a design attitude that goes against hardcore players.
I don't really get the quiet moments people seem to comment on the most, but I do have some memorable adventuring moments - like the first time I paraglided across the chasm in the upper left of the map, I turned the camera around to see how far I dropped and there was a GIANT DRAGON (Dinraal) right behind me. I'd seen Farosh in the distance without knowing what it was, but that jump scare was the first one I'd seen close up and didn't yet know they don't attack you.
I remember being brought to tears standing on a hillside in TOTK looking at a double rainbow across the valley as rain came down while the sun was shining. Despite its dated graphics, it somehow manages to feel more immersive than even the most impressive current gen titles out there.
Basically, BOTW is "poetry" because it is heavily vibes based, at a time when a lot of games are "story" based. My most memorable moments of BOTW are exactly what you described, standing on plateau watching the sunset, walking towards hyrule castle in the rain, finally ready to face Ganon and the zelda theme starts to play, etc, etc. Not specific story reveals but the moment to moment feelings that originate organically from the world and the unscripted interactions and events occurring within it.