Imagine I am standing in Yosemite National Park (about 1200 square miles).
Imagine that I am looking for a rare blue spotted spider the size of a pin head.
Imagine that I reach in my pocket, take out my wallet and look into it, and find no blue spotted spider.
THAT is about how much we have investigated the search for aliens with hard evidence. From a human’s standpoint, just our own Milky Way Galaxy is unimaginably large and old. And there are BILLIONS of Galaxies in the Observable Universe.
So, are there rare, blue spotted spiders in Yosemite? Unless I am unbelievably lucky and find one in my wallet, I cannot draw a definitive conclusion.
Are there aliens “out there”? We have not been lucky so far, but our sample size is so vanishingly small compared to the work area, we can draw no definitive conclusion.
Your assessment is exactly what I was thinking after reading "In spite all of that, ..." All what? We've barely gotten out of bed and wiped the sleep out of our eyes when it comes to searching for life in the "universe."
That said...
Imagine that I am looking for a rare blue spotted spider the size of a pin head.
Some years ago I was camping with a friend. While he tended the campfire I laid down on the ground with my head about a foot from a Juniper bush. My eyes drifted towards a Juniper branch and on a needle of that bush I noticed a tiny movement. It turned out to be a spider slightly smaller than the width of the Juniper needle and slightly paler green. That would be about 1 mm in size. I had to wonder if anyone had ever seen a 'Juniper needle spider' before.