To add, yes they are both very different games, even though you could lump 'em together under the 'open world' tag. Different strokes for different folks n' all that. Don't wanna rat on the Witcher too much, but I (personally) thought that game was kinda dire, except for the aforementioned writing and characters. To further my post from the previous pages, Zelda offers the more provoking experience, for me personally.
To give some context (and hopefully this isn't too spoiler-y, though the game makes this wholly apparent within the first minute), the first thing I did was to try and infiltrate the final level (for all intents and purposes) of the game, because the game allows you as a player to do that. Hopefully that gives you some idea about the level of freeform design that game offers.
In contrast to something like the Witcher 3 for example, you have to go from one story beat to another, and repeating the same 'process' that entails (from cut scene, to quest log, to roach, to fast travel, to roach gain, to holding button to see red glow-y thing, to combat, to cut scene again.) Obviously this problem isn't mutually exclusive to the Witcher (basically every 'open world' game
suffers from this, that Horizon Zero Dawn game felt even worse...), and I'm not saying what your experience during that game-play loop was necessarily bad, but it just doesn't do anything for me, unless it really, really excels (Vampire Bloodlines, for example.) That kinda stuff can be experience just as well in a book, etc., whereas BotW offers something that only games can offer (interactivity, sense of discovery, whatever...), which is why many people are so invested in it (just because it has 'poor' graphics doesn't mean it can be immersive.)
And yeah, might as well stated too that I'm not a fan of the Zelda games either, only really played Zelda 3 and Majora's Mask, haven't bothered with anything inbetween up until this point
