Zelda not having competition is wrong - Competition exists on other platforms as well, not just on the same consoles. Horizon is a direct competitor to Zelda. Yes on Switch itself it has no real competition, but elsewhere is a completely different story.
And again, Zelda is limited by both installbase and supply constraints on Switch. If Switch launched with 3 million consoles day 1, how much do you doubt that Zelda would've sold on at least 80% of those? But it didn't, and most people can't even find one. This isn't the case for Horizon. On top of that, people on Switch have to put down $300 to get to Zelda.
Horizon having other games on the system released months and years ago isn't direct competition. Most people will buy new games later on and not say 'oh, I got Uncharted 4, so I don't need horizon'. What competes with horizon are games released close to its release, not the entirety of the library released prior. That's just crap logic.
