Five hundred years is barely a blink f the eye in the billions of years of the "verse so I can't see why another 500 years would necessarily change whether we find other intelligent species or they find us. I believe they are out there somewhere but not necessarily contemporary with us.Maybe they've been and gone, maybe they haven't evolved yet'
It will be 500 years or more at our present rate of development to be able to travel the distances or at the speeds that Serenity and Moya do routinely. It will take some major breakthrough in physics and our current knowledge of quantum physics is neglible.
In a very literal sense ,I cannot see a jury riggged engine like Kallie keeps going, in the same room with her so it's not nuclear, and what is the fuel source??????, allowing a ship to do what Serenity pretends to do. Nor can I see a living ship, with no observable source of energy , do what Moya can do.
My point was, I found it hard to believe that pioneers or colonists from that very high tech society would be herding cattle,riding horses and talking and dressing like John Wayne.Sure there were touches here and ther, like the hologram window or hovercar, but why the 1880s clothing styles? My other point was that I like aliens--they are a big part of a lot of sci fi. That and robots which weren't there either.
But I got over it, and I enjoyed the interactions of the cast members as I did those in Farscape-- and I miss both of them/