The chances a SkIneos rider winning GC is probably better than even and it's been that way at least since Nibali won in 2014 so yes who's going to be on the top step in yellow is pretty predictable although not certain. The yellow jersey is iconic and what the general mass of public focus on to the exclusion of everything else.
SkIneos are dominant (a) because they have the most money and (b) because their one and only objective is to have a rider win the GC.