There are benchmarks in this space. You can also bring your chip designs into the open and show what happens with different tools. You can run the algorithm on the placed designs that you sponsor for open source VLSI to show how much better they are.

None of this has been done. This is table stakes if you want to talk about your EDA algorithm advancement. If this weren't coming out of Google, everybody would laugh it out of the room (see what happened to a similar publication with similar claims from a Chinese source--everybody dismissed it out of hand--rightfully so even though that paper was MUCH better than anything Google has promulgated).

Extraordinary claims require extraordinary evidence. Nothing about AlphaChip even reaches ordinary evidence.

If they hadn't gotten a publication in Nature for effectively a failure, this would be way less contentious.