That sums it up. Enjoyment comes from core game play mechanics, not quest content. I'd be just as happy with core Street Fighter mechanics in an open world, with no-explanation filler content between boss encounters.
A lot of games genres could make for good open worlds other than FPSes/action games/action RPG's. Would love to see a Mario open world (Bowser's Fury being a sort of proto example).
That sums it up. Enjoyment comes from core game play mechanics, not quest content. I'd be just as happy with core Street Fighter mechanics in an open world, with no-explanation filler content between boss encounters.