It's silly statements like this result that mean that the field isn't taken seriously.

1. How exactly do we know that life must result from "similar circumstances" to ours?

2. How probable are these "similar circumstances" in the universe?

3. What "circumstances" are essential and what aren't?

4. And given these "similar circumstances", what are the chances that intelligent alien life actually evolves?

Given that we have one example of life, and no examples of "similar circumstances" that we can study at all, then all we can say is that the chances of 2 and 4 are "greater the zero".

For example, we have literally no way to know whether 4 is "close to 100%" or "a chance in a billion" - or even to guess which is more accurate!

The interesting question for me is 1. There could be all sorts of environments wildly different from ours that might support life.

Take the surface of a star. Clearly, chemical life seems unlikely there, but there is stability, there is chaos, and there are large energy gradients - these three conditions are "natural" for life to evolve.

Is it possible? Who knows?

Non-water chemical-based life - non-liquid chemical-based life - how probably are they? Who knows?

So there's really not much to talk about here, absent any hard evidence at all, or any way to get some, or any model that makes testable predictions.