BotW had a lot of good things going for it. The basic mechanics of the combat were good. The world was a joy to explore (though that appeal goes away once you've seen everything there is to see). The visuals were lovely. The survival mechanics and interactivity with the environments were interesting. But while the game has a solid foundation, the rest of the structure is lacking. Degrading weapons that break over time. No proper themed dungeons. Limited roster of enemy types by series standards. Heart pieces earned by completing a bunch of repetitive mini-shrines. And of course certain elements that are typical of open-world tedium, including climbing towers to be able to view parts of the world map and having to gather resources to craft things, expand your inventory slots, etc.
It's a decent enough game, but in my book it's not even the best Zelda game, much less in the running for best game ever. Overall, I give it a 7/10.