I think that is very true
The scale of the universe is a compelling reason to assume that life exists somewhere other then earth. The
'rare earth' hypothesis suggests that life requires earth-like planets, and we have been discovering them for some time now, so there are plenty of possible homes for life that we could comprehend as such. I think there could exist forms of life that we would never recognise, and I think these may also exist on earth too. I won't ever know that though.
I think the whole aliens visiting earth scenario is unlikely. Looking at the
Fermi paradox, it seems probable that advanced life capable of such travel; does not exist in the Milky Way yet. It always appears that aliens are flying physical spaceships but there is really no known means for craft to traverse such huge intergalactic distances (yet I suppose) in a timely manner; even lightspeed is too slow to make this feasible and the relativistic time dilation effects of such would cause huge cultural problems for the visitors. I can't really imagine why a ship or craft would be needed if lifeforms are able to bypass traditional spacetime in some way; that seems to be anthropocentric bias. I think the humanoid descriptions are also somewhat anthropocentric (there is no really compelling to think aliens should be humanoid; look at the utter dearth of humanoid creatures on earth itself as an example of the rarity of such creatures), plus the fact that these aliens seem to have discernibly human motives for travel and abductions (research, sample gathering, etc.) might reflect a human basis for these encounters.
But at the same time, there could be alien civilisations similar to our own that exist 100 light years away and we would have no way of knowing. The galaxy may be teeming with semi-modern life like our own and we wouldn't know. Or we could be the first civilisation in the galaxy (or universe) to emerge. I think that if the universe is real in the way it seems, there is certainly other forms of life out there.
I think the idea of panspermia is very interesting, directed panspermia even more so... Its tantalisingly beautiful as an idea