It’s easy, the whole theory hinges on conditions that existed 3.8 billion years ago, according to scientists and their theory of how life arose from non-life around this time. Natural conditions today are not that of what they were 3.8 billion years ago. And they won’t ever be those conditions ever again. You can never prove it.
And the experiment itself is proof that a guiding intelligence is required to get this to work. Nobody has ever found this occurring in the world on its own because the conditions don’t exist anymore. The conditions have to be engineered. If they did find a place (which they won’t, you can’t turn the clock back 3.8 billion years) we’d have heard about it night and day for a solid week.
And the experiment itself is proof that a guiding intelligence is required to get this to work.
Again, the same fallacy. If you can never prove something then you cannot surmise anything from that. If can not prove non-intelligence, you cannot prove intelligence. You can't prove anything.
You defeat your own arguments before I even have to deal with the scientific errors in your statements.
And when you get into "proof" you get into philosophy, not science.