Don't really think you can compare Witcher 3 and Zelda just because they are both "open-world"…
I mean, does Witcher have many unique dungeons, full of environmental and item puzzles, locked doors that require hidden keys, hidden treasure items that are used throughout the entire game to solve future puzzles (a hookshot that acts like Batman's grappling hook, an Ice Staff that freezes enemies, a bow that you have to manually aim to hit certain targets, etc.?)
I'm just talking about older Zelda games. The new one is different as it may or may not have a Hook Shot, etc.. It has a magnetism item that lets you move large metal objects around, solve puzzles using that, or create new paths to travel (placing a large metal door to repair a bridge across dangerous water, etc..) I'm not sure how cooking is implemented but it likely has some serious gameplay affect (I saw that one cooking dish gave cold resistance, which may be mandatory to travel in the frigid areas.)
For past games, you had many temples that were quite treacherous and brain-teasing to explore. You had to use reflex and smarts in combat, often having to hit a certain weak point or time your attack well. On top of that the dungeons were full of puzzles, secrets, sometimes challenging to the point people couldn't figure out how to complete them for many hours. The world itself has secrets galore, hidden items, heart pieces that raise your health, even hidden fairies that upgrade your equipment if you can find their locations. Ocarina of Time had an element where you had to learn songs for the Ocarina in the game and play them at certain times to make environmental events happen (temples rising from the ground, entire lakes draining of water to reveal a hidden temple and so on.)
So the Zelda games have pretty much always been innovative games, from the first Zelda to present day. Maybe try playing the games and see what they are about. I've always been a fan but haven't really played much Zelda since Twilight Princess on the Wii (which also had an interesting element of being able to travel to and from the "netherworld" type area. This feature was also used for the Magic Mirror in Link to the Past on SNES, where you could travel to and from the Dark World, often using it to solve puzzles, find secrets, etc.. The Dark World in that game even had an entire map to explore that paralleled the Light World, but was full of deformed monsters, twisted, gnarled trees and had a whole weird and creepy spin on the Light World. Pretty amazing stuff at the time.)