Yet to play the game but it certainly seems to be a true classic.
HOWEVER. It's too early to say really, and it still annoys me with people calling it the greatest game of all time, or a classic.
Say what you love about it, and then in 10 years tell me its a classic.
I mean... if you play it, you'll understand why it's fairly non-controversial to call this game a classic. This game is up there with stuff like Chrono Trigger, Super Metroid, Mario 64, Halo CE, etc. It's definitely got that magic factor.
It reminds me of the first time I played Super Mario Bros. 3 as a kid. I was playing for months, getting further and further each time (remember there was no save feature on the original NES version) and I came to the world with Giant enemies called Giant Land. After months of playing the game, I had no idea I would see giant enemies like that. It blew my mind! In fact, I'd never seen giant enemies like that in a game prior to SMB3. It really felt like I discovered something new and the game constantly surprised you with stuff like that: The angry sun, pipe world, giant land, hidden whistles, a vine that led to a second half of World 5, the tanooki suit, random ship full of coins that appeared on the map, etc.
Zelda is like having all of those shocking things to discover in a modern open world with tight gameplay. Every area really feels distinct which is impressive considering just how huge this game really is. You will
constantly be shocked with the stuff you find the first time you play it.
The problem with talking about BotW in specifics, however, is that revealing why it's so great has the potential to spoil a lot of the game. It has a lot to do with the places you discover more so than the mechanics (which are also very much an accomplishment in their own right). But, it's really safe to say that they made this world feel very lush and magical in a very "Nintendo" like way.
You just really need to play it.