My joke and SF aside, I do consider several realistic issues, which are related and should not be ignored.
First, the word ever in the title implies... ever. Also, you can make rockets faster and fuels more efficient, but when dealing with the immensly large distances, a single trip to the nearest star would take at least a lifetime. In my opinion it's a waste of a lifespan just to see one new celestial body upclose, before succumbing to old age.
That's when radical thinking comes in. Take Tesla, instead of investing effort into generating energy, he simply harvested it from Earth's magnetic field with a simple coil while reading a book.
Second, given the knowledge we already poses for decades, like atomic energy and it's a nice one, although bares certain risks, we already might had reached more sophisticated levels. We went to the moon, but not because we could, but because we wanted to play a game with the Russians. Imagine if we really did so because we wanted to expand our conciousness and insights. We would already have commerce and industry over there. Which takes me to the third point, so please bare with me.
Science these days is politicized, biased and only enabled with funding. No money, no science. Also those who fund science, do that for their own interest, rather than everyones. Weapons always come first. I hope that Elon Musk becomes an exception, but he's still the only one.
These are the issues that have a major influence on the development of any technology, and in order to let science expand to limitless proportions, one should fix these issues first. Otherwise, considering any reasonable advancements for all to share in a lifespan equals to science fiction, if that's what you refer to with SF.
I'm not being pessimistic, just realistic with a pinch of "not taking things to seriously".