> NB I'd expect none of these very simple machines to survive to present day - in fact, I'd imagine there to be several generations of early life, each obliterating/consuming/sublimating the ones before.

That's another really interesting axis of this topic -- why was early Earth special?

There may be no environments on Earth today that are like early Earth, but we could probably recreate them. Wouldn't we then be able to witness abiogenesis?

Or, early Earth wasn't special and abiogenesis happens today. If so, where do we look?