Had it not pulled a Wii

A good expression for the situation. Wingspan's success is definitly to a large part because of it's accessibility. Every problem you have (no cards, food, eggs) has an immediate, guaranteed and obvious solution. Everything you CAN do improves your position. And if you play on the blue side there is barely any direct competition in the game. There's no way to shoot yourself in the foot. There is no requirement to plan ahead.

But it does have some potential to plan ahead, optimize and compete for those who want to.

It also doesn't fall into any of the typical setting tropes like fantasy or sci-fi that might put some people off. It's production values are pretty enough to catch some eyes.