You call these factors "circumstantial evidence", but they are only circumstantial evidence if our ideas about what allows/causes/etc life are correct, which we

You call these factors "circumstantial evidence", but they are only circumstantial evidence if our ideas about what allows/causes/etc life are correct, which we have not validated at all. If we can't promote abiogenesis in a lab our understanding is clearly limited, which is itself surprising. How many other processes in nature have we observed and not been able to replicate ourselves (or at least make progress towards replicating)?