Me too. You're smart enough to know that only one life model is known to us. All others are 100% speculative. The fact amino acids and other building blocks for life have been found, but we can't even find life, past or present, in our own Solar System despite looking for decades. Sure, one day microbes might be found in Mars or growing in the oceans of Io or Europa. If so, then we'll have a second model of life.
That's not the point of Fermi's Paradox. As noted earlier, our solar system is less than half the age of our galaxy's oldest stars. Over 4.5 Billion years is a long, long time. Again, as noted before, where human beings likely to be in as little as 10,000 years much less 500,000 years or 9 times that much time.
There should be something. Some kind of signal, evidence. Dyson hypothesized to look for stars "winking out" due to Dyson spheres or just having their light diminished with a ring. Nothing. Nada. Zip. Zero evidence of life in the entire Universe except for our own.
This doesn't mean there isn't because no one knows, but I think there are other possibilities as to why we haven't found that evidence. A common (Star Trek) idea might be some sort of Prime Directive.
A less common idea is that advanced civilizations don't use tech. For all we know the highest form of life were the Neanderthals and Homo Sapiens killed them off. Ours is a very technological species. We've successfully killed off or subjugated all other human cultures and animal species with Tech. What if "Tech" is considered barbaric by advanced cultures? That they've developed another path which is why we can't find them?
