Can’t Ganondorf and Zelda just be really good friends? Can’t they just watch nature documentaries on Netflix and gossip while they braid each other’s hair? Does Ganondorf’s dick really have to be involved in their relationship?

Yes, yes, no. You can always fade to black. There's plenty of smut out there, and I think for certain stories it's best to avoid adding smut to the equation. I certainly wouldn't add it if I didn't want to write it.