Good point. New Horizons isn’t doing multiple large planet flybys and pluto doesn’t have the gravity well to give much boost.
We really are in the horse and buggy days of space travel as long as we’re stuck with rockets.
Well, its not that we can’t go faster, its just that’s never been a stated objective. There are many theorhetical designs we have, that could reach close to light speed over time.. of course, then the question becomes.. how do you slow and stop the thing?
I remember years ago reading about an engine design for close to light speed, accelleration was achieved if I remember correctly by single molecule releases by the engine over time, this would over time get the space craft eventually to close to light speed, obviously this accelleration would happen over long periods of time, but it would get you there, and was plausible to launch with enough fuel to accomplish. Of course then the issue is, slowing it down in time and all the other stuff it would have to do automatically since no realistic control could be offered from earth with lag time of communication being measured in years.
Interstellar travel just hasn’t been a goal. In terms of interstellar travel, we aren’t even in the horse and buggy stage yet, more like the unsandled foot on an unpaved road.