PC was "separate" from console yet bringing FPS games to console properly was significant. By the same token, so is bringing massive open world experiences to mobile.

And no other open world game functions in the way that BOTW does.

Because FPS was optimized for KB/M. Adapting FPS to dual analogs (and southpaw before it) was groundbreaking in that it made an accurate shooter on console. BotW is the exact same controls of an open world but on a handheld.

Right, they all have their own little quirks, but I'd hardly consider fire physics and brittle weapons groundbreaking.

But you'd never been able to take a massive AAA open world experience with you in the palm of your hands before. It's the same thing; bringing one kind of experience to a new kind of platform.

And please, if you're going to discuss this, at least be serious, we both know that reducing BOTW's multiplicative systems-driven gameplay to two random elements is disingenuous. 

That doesn't make it groundbreaking, at very least not in the same realm as SM64 perfecting the 3D platformer genre.

Honestly, BotW hasn't done anything that other open world games haven't done at some point. Literally every element in BotW is present elsewhere. It's not revolutionary, it's just a masterpiece. Sometimes things don't have to be unique or "first" to be the best. Sometimes they just have to be well crafted.

Mario 64 wasn't the first 3D platformer. Halo wasn't the first console FPS. Mario Bros wasn't the first platformer. They just all took a new approach that made them work better than previous attempts. BOTW does the same. There had been open world games with some physics before, but none had ever incorporated such an organic unified system of physics and chemistry that allowed for exponential gameplay possibilities.

Mario 64 showed everyone a proper 3D platformer when Crash was still under the impression that a linear route was the only option.

Halo introduced the idea of regenerating health in FPS, something that literally every FPS does nowadays. Halo 2 also kicked online console shooters into the mainstream during a generation where not every platform even came with a modem.

Mario Bros just happened to do it correctly and in a format that everyone began to copy.

The difference here is BotW isn't being copied. It was the one that copied. No ground was broken, only perfected.

Actually multiple games have borrowed from BOTW, but that's beside the point. Even if nobody tried to copy it, that wouldn't change the fact that it did new things.

What did it do that was new? 

I feel like there's something people are overlooking with BOTW; it was the first time that a complex, HD/AAA open world game was playable on a handheld. That in itself is a pretty significant breakthrough for gaming.