Taking favourite novels which are within arm's reach: Sure "Rainbows End" is Science Fiction which doesn't involve space travel etc. but "Incandescence" is also SF but that's deeply about space travel. Banks' "Whit" and "Surface Detail" are both sat here. One of those is set in a lightly fictionalized Scotland and the other is a Science Fiction novel where the main protagonist dies but is resurrected, then is witness to several of the most significant space battles of her era. But like, if you didn't know, how would you guess which is which?
Now, Banks wasn't a hard SF writer. Unlike say Egan's "Incandescence" none of the events of his SF novels are actually physically plausible, but presumably this list is about genre SF and thus includes Banks, Bujold etc.
Banks might not have focused on the hard sci-fi aspects but I have a difficult time imagining a more likely future for humanity than something like the culture civilization.
Egan's "The Amalgam" is an SF society which could in principle descend in part from some future humanity, and I suppose if you like Banks' setting for its utopianism you'd be satisfied with the Amalgam. Its citizens tend to live long, full lives in which they're definitely mostly concerned with the upper parts of Maslow's pyramid and their practical needs are fulfilled as a matter of course in most cases.
I must say, to the extent we have any future at all, I think probably of Egan's "Dream Apes". An Orangutan-like self-engineered future humanity who have arranged that there are no apex predators above them, there's an abundance of resources for their relatively modest population, and they just chill, believing that if there is something out there it's not their concern. Of course in the story the Dream Apes are all annihilated by a cataclysmic event which destroys Earth, but hey, it's pretty quick.
Probably not best sci-fi universe one can come up to. Or most selling one.
no publisher was there to tell author "wtf did you name it, you'll get ignored" or smth?
Another interpretation might be that as fewer books are released in a subgenre, their titles also become more abstract, which would increase the effect seen in the data presented as well.
But I would hesitate to believe that the observed effect should be chalked up to only title abstraction, and not a decline in popularity. Occam’s razor.