Zelda can't win this.
I played a heavily modded version of TW3 with better visuals than vanilla running a solid 4K/60, immersion mods, combat mods, AI mods, and UI mods all making the game even better than vanilla. BotW runs at a shit framerate, shit resolution and looks comparatively simple. In terms of sheer performance Geralt drags his nuts across Link's face.
I still liked Breath of the Wild more.
I have 280 hours in The Witcher 3 not including the hours I spent tinkering with mods to make it better, and about the same hours in Breath of the Wild. I likely won't ever play TW3 again, but I already have a feeling of nostalgia regarding BotW and know I'll be back before the sequel arrives.