missed this one:
Exactly. They are arguing that the biological systems we have now are too irreducibly complex to have evolved from undifferentiated chemical mixtures and structures, therefore abiogenesis was essentially impossible - the tornado in a junkyard scenario.
It's an obviously invalid argument, debunked in all its previous forms - the eyeball, the wing, the blood clotting mechanism, etc. As Alex put it:
Side note: one way to see immediately where you have gone wrong is by noticing this: "biological usefulness" of molecules is an irrelevant concept in abiogenesis - we are talking about the evolution of nonliving chemical complexes, and their future "usefulness" is completely beside the point. As soon as you use the term, you are going wrong.
Side side note: one obvious counter to "showing complexity does not establish a designer" would be "intelligent design does not require a designer" - but that never occurred to you, did it? That's because you're an Abrahamic monotheist.