the way upon video games are rated on their success and quality is largely subjective - do you value gameplay - or a good story, and allow gameplay which may not be the best to be forgiven for an engrossing tale?
do i think rdr2 should've won over fortnite? of course; as an exercise in storytelling and balance of gameplay, rdr2 has been largely unrivaled this year. not as deeply satirical as other games like gta 5, and instead having moments that resonate as deeply poignant.
do i think rdr2 would've won over a naughty dog game or something by kojima? hard to tell, it's a toss up; naughty dog has turned into disgusting shills for spoonfed LGBTQ tropes, but the masses eat it up still. kojima is just loved by all, even if i personally think he's a pretentious fuck at some points.
at the end of the day it's personal preference in terms of the balance of storytelling to gameplay, and who's making the game. you can't deny that rockstar would win over an indie game equal in quality purely because they're rockstar. don't pay attention to critics and formulate your own opinion.