Breath of the Wild’s insane word of mouth gives it an incredible hold.
Usually, games that are older sell fewer than newer games. Newer games come in, get most of the media attention and word of mouth, and sales of older games trail off. There are, of course, exceptions to this- games like Rocket League, Minecraft, GTA, The Elder Scrolls, plus, of course, Nintendo games, especially Mario.
As far as Nintendo games go, though, Zelda tends to be the least leggiest franchise they have- in fact, the sales for Zelda tend to behave the most like a standard AAA game out of all Nintendo franchises. So take this, plus Mario‘s legginess, plus Zelda being older, and you’d expect Breath of the Wild to be selling at a lower rate now than Super Mario Odyssey is.
Except it’s the exact opposite- in the last quarter, with 840,000 copies sold worldwide, Breath of the Wild outdid Super Mario Odyssey, which did 760,000 units in comparison. Odyssey still has the higher lifetime sales, but its sales seem to be slowing down, while Zelda holds steady (something we see in sales charts rankings such as Media Create and NPD, too).
I think, in the end, this comes down to the insane word of mouth that Breath of the Wild had- while Mario got a lot of praise too, it was just “a great Mario game”, versus “one of the greatest games ever made” with Zelda, which is the kind of praise the game continues to get with the general public to this day. That said, while I expect Breath of the Wild to continue to sell great for years to come, I do think that, in the end, Odyssey will have the higher lifetime sales.
Both games are available now on Nintendo Switch.