For Halo to be Halo everything has to be a home run. PlayStation has never delivered on a first party package that Halo strives to be. It’s huge shoes to fill that even 343 struggles to achieve but the ambition is there. Meanwhile Sony does a AAA fire and forget campaign and that’s considered a gold standard.
On the one hand, yes, Sony's games are really excellent 20-45 hours of gameplay that you play once, maybe twice, and then you're done with, while there are people who sink thousands of hours into Halo. One's primarily a cinematic showcase with gameplay, tuned to highlight that cinematic quality and the other is tuned primarily for multiplayer gameplay. Halo's not the game that people should compare to Horizon; even if 343 somehow managed to become 95% as talented, they're targeting a different framerate, and a different experience and they need to nail that 60fps/120fps gameplay and have it look good (spoiler: they didn't as of the last time).
Where MS would need to be able to compare with HZD in that cinematic area are games like Avowed or Hellblade or the Fable remake, etc. I think they could theoretically come close with Hellblade, but that's probably two years away. I don't know that any of them will pull that off, though. (edit: I'd probably bet against it, in fact)
OF course, I'll probably play them all (scratch that: I will play those three). If the gameplay is great and it's slightly less pretty than Horizon or whatever else, it won't mean I enjoy it less.
[edit 2: And on the other hand, what's the Sony game that people are going to sink 200+ hours into? Compare Halo to that.]