What it's really about now is the combination of certain game mechanics. You've played a Bethesda game, and you've played a space sim, but you haven't played a Bethesda game in a space setting with ship construction, planet exploration and resource extraction outpost building, or really any light space sim with solid first person shooting at all.
To me, that combination is novel. Just like AC Odyssey's fusion of a true stealth game and an open world setting is novel and doesn't exist. The particular parts that make up the whole are not novel, the combination and execution are. There is still new ground to cover there.