Sci-Fi Odyssey on YouTube asks Are We Losing The Essence Of Science Fiction? The answer is probably no, but I'm sharing to discuss.
A Rod Sterling quote sums up my position, "It is said that science fiction and fantasy are two different thing. Science fiction is the the improbable made possible, and fantasy is the the impossible made probable."
So a lot of SF/Sci-Fi/speculative fiction meets that criteria. What we are then left with is taste.
My SF is better than your SF because mine has maths/literary merit/deals with serious issues etc. And here is where Sturgeon's Law comes into play, 90% of everything is trash.
My perspective is that human beings are not capable of being rational about subjects (see Professor Sapolsky's lectures for the gribbly detail). To simplify, the ideal may be infinite diversity in infinite combination, but humans can't handle an infinite number of diverse combinations.
My conclusion led me to write my own SF books, and I can say that what I like to write is not necessarily what people like to read.
