That probably begs a little clarification, doesn't it?
Specifically, I write science fiction and fantasy exactly the same way--through a sort of logical and creative extrapolation from a base set of assumptions. This set of assumptions can be the current world (as it is in Hammered and Blood and Iron) or something quite different (in the Eddas books, the worldbuilding is heavily extrapolated off of Norse myth, and in Carnival, it's extrapolated off... well, the intersection of several mutually contradictory sets of SFnal tropes.) but it's always the same process. Something twigs my attention, and somewhere in the back of my head a switch flips, and the worldbuilding starts.
I think, by some sort of arcane technical definition, that makes me a fantasist rather than a science fiction or fantasy writer.
Whether it comes out fantasy or science fiction doesn't actually seem to affect the nature of the process, or the rules. It affects the foundations (in a fantasy, certain types of magic will work, for example, based on the milieu--in an Norse fantasy, it may be seithr or rune magic, and in a Celtic fantasy there is likely to be magic based on geasa and song--whereas in a science fiction story, the types of magic that work are already strictly delineated by a set of existing genre conventions--which is why alternate history is "science fiction," and second world fantasy is "fantasy." Because it kind of feels that way.) but then again, to me, science fiction is a type of fantasy. Specifically, it is a subset of fantastic literature that has its own rules and conventions (like, say, magic realism, or fairy-tales)
So to me, science fiction and fantasy are more or less marketing categories, but the structures behind them aren't that different. Just a few conventions of magic apart. It just depends on whether I take as my postulates the laws of physics, or the poetic Eddas.
I'm not sure science fiction is, entirely, about the relationship between man and technology any more. I dunno, actually, in general--I can't much make pronouncements about the State of the Genre. Because I think everybody working in it is up to their own thing, making a sort of glorious mess, exploring the aspects of genre that catch their eye. So you have people going after the pulp tradition, and others writing very rigorous SF that they believe to be extrapolative, and so on.
I can talk about my own work, of course, and that's generally speaking more about transformations and personal relationships and how people cope with an ever-changing society than it is about anything else. And I wonder if that's a generational thing in some ways, because people in my age group tend to be pretty integrated into the technological world. It's not so much a race to keep up and integrate as it is picking and choosing the things that are interesting and useful and cool. Technology's not going to save us, but there's also less a sense that it's The Big Threat about to overrun us, also.
It's a tool. Like a hammer. And like a hammer, it can be used to build a house, or bash in a skull.