Another quote from that Kim Stanley Robinson interview:
Another useful conceptual tool is protagonicity. Does a novel have high protagonicity or low protagonicity—meaning the story is maybe spread out among a lot of different characters, who might be considered minor characters, except there aren’t any major characters. The story I intend to tell determines or suggests how I might go about deciding this.
Mountain Song, Claudio La Rocco via BookForum
Maybe because my original writing background is in short fiction, I find myself biasing towards 'high protagonicity' when thinking about new story concepts. Actually, expanding that thought, it's probably also influenced heavily by games. This is a snap response rather than an explored thought, but I'd expect that games bias high protagonicity, by Robinson's definition, due to the role the player tends to occupy in relation to the story. The player character almost always acts a singular lens for the player to experience the story, and there are lots of by-this-point tropey narrative conceits to justify why the player is uniquely positioned to find that artefact/kill those rats/help this NPC find love.
(There are games that play with these ideas, of course, but offhand still with reference to the player character centred as protagonist.)
But, to immediately counter my own theory, the picture gets complicated when the player character is a cipher or else silent and where their relation to the narrative really comes down to the actions they are required to perform (which Only They Can Perform). That feels more like a weird collision of both high and low protagonicity, where so much is concentrated in one individual, but the means by which the story is told is in a lower-protagonicity way by NPCs with more dramatic range and narrative-if-not-actiony agency.
There are certainly some games that deliberately steer into low protagonicity more deliberately. The first one that sprung to mind was Fahrenheit/Indigo Prophecy, a game I played while in the throes of a high fever as a young adult and so which I'm not entirely convinced is real.
Other (vomiting from the eyes emoji) Quantic Dream games do this too, leaning into storytelling with low protagonicity (e.g. vomiting from the soul emoji Detroit: Become Human). But I wonder if that's also wrapped up in the way those games so frantically borrow storytelling techniques from film in particular, a clutch that I think would risk seriously hampering their efforts if they had anything going for them to begin with.