Question

Reasons why mystery fiction is better than science fiction

Answer 1

I'd call it a sign o' the times. There was a time, many decades ago, when science fiction dazzled us, because it was about the future; maybe OUR future. In fact, science fiction was once called the only inherently optimistic genre, because it assumed we WOULD have a future.
Brilliantly reasoned technologies were woven in with stories of how we coped with these things and the circumstances of such worlds. Among the best of these tales, the progression of how the technology of that time---of when the story was written--- became that future technology was explained. It inspired designers, physicists, and engineers, besides being fun to read.
That was then, and as is the way of things, times change. Now we're in the future those writers predicted, and it is stranger and more wondrous than they imagined... but to us, it's just another day.
Surrounded by---or even wearing---advanced technology that could once have been the center of a scifi story, people today tend to want stories about how to handle emotions and relationships, how to deal with overwhelming concepts, and how to find out who they are in our world of cheap tech and easy leisure.
Fantasy uses hand-waving (though often very carefully structured by writers who care about their canon) to get to the meat and potatoes of things: how people work.
I also should say that a great deal of what people think of as scifi IS fantasy. Star Wars is just a classic fantasy with some spaceships zooming around. It is a multi-generational family saga about good guys and bad guys and their allies. Nothing science-y about it.