Of course scale matters, how many times have you seen me praise FF16 and Spiderman's scale and setpieces? But if it was the only thing mattered than Alan Wake 1 would beat out Alan Wake 2 for best graphics. It had far larger environments. By that logic, a game like TLOU2 could never win goty over an open world game. Lets give 2020 graphics of the year to Watch Dogs legion, shall we?
AW2 beat out other games on his list because it does everything better. Cutscenes fidelity, level of detail, object quality, character quality, lighting, AND the scale is all very impressive. Again, dead Space and Callisto dont have the bright falls area you are exploring. There are several areas that are so large you need a map to explore them all and it is consistently great looking regardless of where you are, in a tiny bedroom or an outdoor area with lots of foliage or in the middle of NYC streets.
I assumed people realized that i was talking about graphics of the year, not game of the year.