You’ve gone from accusing me of a straw man argument, to postulating that not only do the Stargate Replicators exist, but every other advanced civilization knows they exist but somehow hide from them, even though by all conservative estimates, if Von Neuman probes did in fact exist, more than enough time has elapsed that the entire galaxy should have been converted to a grey goo by now.

Replicator machines “seem doable”?!?

Explain. Seriously. Explain what technologies and energy sources would create a complex autonomous machines from unrefined raw materials.

If it’s easier, explain how you’d make make a paper clip from first principles in the middle of a Greenland glacier. What are you going to do? Use electrolysis to split the water, and then have a fusion device fuse hydrogen into iron? Scrape across the surface to find trace atoms, and hope you find enough iron? Even if you have the iron, are you going smelt it, or what? How do you plan to forge it into steel, and then shape it? Are you going to use a tunneling electron microscope to place individual atoms? What’s the energy budget for this? How are you collecting and storing it? What’s the mass of this machine?

At this point, we’re talking about a World Devastator from Star Wars: Dark Empire.

“Seems doable”! Pshaw! EVERY ONE of these thought experiments from the 1940s are just magical premise to base a much simpler analysis on. In the case of Von Neuman proves, it’s determining a limit on how fast you could settle the galaxy. It’s not a serious technical proposal. It never was.