Ask Lemmy

To answer seriously, in my opinion it is the simplicity and accessibility that Nintendo baked into their game. There isn't 10 different systems to learn, or 50 different skills, or even a skill tree. Nintendo made an open world game that was very light on the typical RPG elements that most open world games heavily feature and that made the game very easy for any casual person to pick up and play. This made a lot of sense considering Nintendo's games are targeted at a more casual audience anyway. Now of course this was seen as a negative to the folks who want more mechanical depth in their games but the reality is the casual players still outnumber the more serious crowd and so as a result you hear more from the casual crowd who in turn enjoyed the game for it's simplicity. There's also the brand recognition tied to it. More people are likely to have played a Zelda game in the past and are familiar enough with the franchise to have wanted to go out and purchase the game. I'm sure there are some more in-depth and technical reasons why BotW succeeded they way it did but on a high level I believe these reasons account for a majority of the consensus.