A sample size of 1 means: not a clue.

True that. The argument (at that level) is speculative. But sometimes it can be interesting to speculate.

Even the most basic life seems super complicated to me, I am not sure the first spark of life has that high probability of happening even under right conditions. But maybe I am over estimating its complexity.

People have studied this, and basic building blocks (amino acids) arise spontaneously when electric current is applied to chemical soups for example. Also when we look around today, we see the end prodcut of billions of years of evolution, we don't know what truly primitive life may have looked like in the first few millions years, life forms even more primitive than viruses, say.

Still, a few amino acids are far far away from proteins, let alone all proteins that work together and makes a simple living cell. Or mechanisms like: https://www.nature.com/scitable/topicpage/mitochondria-14053...

it might still be possible "given enough time".

Some of the chemo-synthesizing lifeforms around volcanic vents might be close.

These days we have an industry that makes DNA "oligo"'s that should be somewhat close to how life would have looked at some point in the distant past. The chemical reactions involved in the entire lifecycle are entirely understandable with university chemistry knowledge. Starting the reactions takes a remarkably small number of chemicals present, and none of these are too far fetched.

You have to keep in mind that, on earth, today, life cannot just exist. It must compete successfully with other very complex lifeforms. This effectively imposes a minimum complexity level that any lifeform must attain to survive in the current environment. But, conceptually, there are many things that would count as life even though they have zero hope to exist on earth (outside of labs). Such simple lifeforms today can only exist in places like the clouds of Venus.

One explanation is that life was seeded from space by spores of some sort, and they may be quite common throughout the universe.

We're talking about radio in the article. Which means we're talking about a very small subset of possible life.