Hmmm....
The detection of planets in "habitable zones" is a far cry from habitable planets. But maybe 1/1000 of these would in fact be suitable.
So then the only problem is that it would take five million years to get there.
So you see, it is not possible for humans to find other habitable worlds. But it is possible for the evolutionary processes of life to be spread.
It is still possible since the astronauts already found a planet like earth. If they were able to make a device that can travel that fast without carrying human beings then later on they will surely discover a new device that can travel as fast as the current device. Which can also load up humans.
?No, astronauts have not "already found a planet like earth."
no, nobody has made a device that travels that fast without carrying humans.